diff --git a/CHANGELOG.md b/CHANGELOG.md
index 222a0c3b7c..edc7b56e9b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 ### New features
 
+* [#129](https://github.com/rubocop-hq/rubocop-performance/pull/129): Add new `Performance/BigDecimalString` cop. ([@fatkodima][])
 * [#81](https://github.com/rubocop-hq/rubocop-performance/issues/81): Add new `Performance/StringInclude` cop. ([@fatkodima][])
 * [#123](https://github.com/rubocop-hq/rubocop-performance/pull/123): Add new `Performance/AncestorsInclude` cop. ([@fatkodima][])
 * [#125](https://github.com/rubocop-hq/rubocop-performance/pull/125): Support `Range#member?` method for `Performance/RangeInclude` cop. ([@fatkodima][])
diff --git a/config/default.yml b/config/default.yml
index 943a0f8340..78722a8985 100644
--- a/config/default.yml
+++ b/config/default.yml
@@ -6,6 +6,11 @@ Performance/AncestorsInclude:
   Enabled: true
   VersionAdded: '1.7'
 
+Performance/BigDecimalString:
+  Description: 'Convert numeric argument to string before passing to BigDecimal.'
+  Enabled: true
+  VersionAdded: '1.7'
+
 Performance/BindCall:
   Description: 'Use `bind_call(obj, args, ...)` instead of `bind(obj).call(args, ...)`.'
   Enabled: true
diff --git a/docs/modules/ROOT/pages/cops.adoc b/docs/modules/ROOT/pages/cops.adoc
index 75357f3efc..4f3032097c 100644
--- a/docs/modules/ROOT/pages/cops.adoc
+++ b/docs/modules/ROOT/pages/cops.adoc
@@ -3,6 +3,7 @@
 = Department xref:cops_performance.adoc[Performance]
 
 * xref:cops_performance.adoc#performanceancestorsinclude[Performance/AncestorsInclude]
+* xref:cops_performance.adoc#performancebigdecimalstring[Performance/BigDecimalString]
 * xref:cops_performance.adoc#performancebindcall[Performance/BindCall]
 * xref:cops_performance.adoc#performancecaller[Performance/Caller]
 * xref:cops_performance.adoc#performancecasewhensplat[Performance/CaseWhenSplat]
diff --git a/docs/modules/ROOT/pages/cops_performance.adoc b/docs/modules/ROOT/pages/cops_performance.adoc
index 32a90e0ac0..20fc2493b8 100644
--- a/docs/modules/ROOT/pages/cops_performance.adoc
+++ b/docs/modules/ROOT/pages/cops_performance.adoc
@@ -30,6 +30,36 @@ A <= B
 
 * https://github.com/JuanitoFatas/fast-ruby#ancestorsinclude-vs--code
 
+== Performance/BigDecimalString
+
+|===
+| Enabled by default | Safe | Supports autocorrection | VersionAdded | VersionChanged
+
+| Enabled
+| Yes
+| Yes
+| 1.7
+| -
+|===
+
+This cop identifies places where numeric argument to BigDecimal should be
+converted to string. Initializing from String is faster
+than from Numeric for BigDecimal.
+
+BigDecimal(1, 2)
+BigDecimal(1.2, 3, exception: true)
+
+  # good
+BigDecimal('1', 2)
+BigDecimal('1.2', 3, exception: true)
+
+=== Examples
+
+[source,ruby]
+----
+# bad
+----
+
 == Performance/BindCall
 
 NOTE: Required Ruby version: 2.7
diff --git a/lib/rubocop/cop/performance/big_decimal_string.rb b/lib/rubocop/cop/performance/big_decimal_string.rb
new file mode 100644
index 0000000000..0f33aface9
--- /dev/null
+++ b/lib/rubocop/cop/performance/big_decimal_string.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Performance
+      # This cop identifies places where numeric argument to BigDecimal should be
+      # converted to string. Initializing from String is faster
+      # than from Numeric for BigDecimal.
+      #
+      # @example
+      #
+      #   # bad
+      # BigDecimal(1, 2)
+      # BigDecimal(1.2, 3, exception: true)
+      #
+      #   # good
+      # BigDecimal('1', 2)
+      # BigDecimal('1.2', 3, exception: true)
+      #
+      class BigDecimalString < Cop
+        MSG = 'Convert numeric argument to string before passing to `BigDecimal`.'
+
+        def_node_matcher :big_decimal_string_candidate?, <<~PATTERN
+          (send nil? :BigDecimal $numeric_type? ...)
+        PATTERN
+
+        def on_send(node)
+          big_decimal_string_candidate?(node) do |numeric|
+            add_offense(node, location: numeric.source_range)
+          end
+        end
+
+        def autocorrect(node)
+          big_decimal_string_candidate?(node) do |numeric|
+            lambda do |corrector|
+              corrector.wrap(numeric, "'", "'")
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/rubocop/cop/performance_cops.rb b/lib/rubocop/cop/performance_cops.rb
index 1d4b44080f..0f4c33f939 100644
--- a/lib/rubocop/cop/performance_cops.rb
+++ b/lib/rubocop/cop/performance_cops.rb
@@ -3,6 +3,7 @@
 require_relative 'mixin/regexp_metacharacter'
 
 require_relative 'performance/ancestors_include'
+require_relative 'performance/big_decimal_string'
 require_relative 'performance/bind_call'
 require_relative 'performance/caller'
 require_relative 'performance/case_when_splat'
diff --git a/spec/rubocop/cop/performance/big_decimal_string_spec.rb b/spec/rubocop/cop/performance/big_decimal_string_spec.rb
new file mode 100644
index 0000000000..50f66184a8
--- /dev/null
+++ b/spec/rubocop/cop/performance/big_decimal_string_spec.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::Performance::BigDecimalString do
+  subject(:cop) { described_class.new }
+
+  it 'registers an offense and corrects when using `BigDecimal` with integer' do
+    expect_offense(<<~RUBY)
+      BigDecimal(1)
+                 ^ Convert numeric argument to string before passing to `BigDecimal`.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      BigDecimal('1')
+    RUBY
+  end
+
+  it 'registers an offense and corrects when using `BigDecimal` with float' do
+    expect_offense(<<~RUBY)
+      BigDecimal(1.5, 2, exception: true)
+                 ^^^ Convert numeric argument to string before passing to `BigDecimal`.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      BigDecimal('1.5', 2, exception: true)
+    RUBY
+  end
+
+  it 'does not register an offense when using `BigDecimal` with string' do
+    expect_no_offenses(<<~RUBY)
+      BigDecimal('1')
+    RUBY
+  end
+end