diff --git a/pyo3-benches/Cargo.toml b/pyo3-benches/Cargo.toml
index 3ade8ef00e9..3d45a0e4f12 100644
--- a/pyo3-benches/Cargo.toml
+++ b/pyo3-benches/Cargo.toml
@@ -98,4 +98,8 @@ harness = false
 name = "bench_pystring_from_fmt"
 harness = false
 
+[[bench]]
+name = "bench_int128"
+harness = false
+
 [workspace]
diff --git a/pyo3-benches/benches/bench_int128.rs b/pyo3-benches/benches/bench_int128.rs
new file mode 100644
index 00000000000..1bdcd43c432
--- /dev/null
+++ b/pyo3-benches/benches/bench_int128.rs
@@ -0,0 +1,69 @@
+use std::hint::black_box;
+
+use codspeed_criterion_compat::{criterion_group, criterion_main, Bencher, Criterion};
+
+use pyo3::{
+    prelude::*,
+    types::PyInt, conversion::IntoPyObject
+};
+
+fn into_u128(b: &mut Bencher<'_>, value: u128) {
+    Python::attach(|py| {
+        b.iter_with_large_drop(|| black_box(value).into_pyobject(py));
+    });
+}
+
+fn into_i128(b: &mut Bencher<'_>, value: i128) {
+    Python::attach(|py| {
+        b.iter_with_large_drop(|| black_box(value).into_pyobject(py));
+    });
+}
+
+fn extract_u128(b: &mut Bencher<'_>, value: u128) {
+    Python::attach(|py| {
+        let obj: Bound<'_, PyInt> = value.into_pyobject(py).unwrap();
+        b.iter(|| {
+            let v: u128 = black_box(&obj).extract().unwrap();
+            black_box(v)
+        });
+    });
+}
+
+fn extract_i128(b: &mut Bencher<'_>, value: i128) {
+    Python::attach(|py| {
+        let obj: Bound<'_, PyInt> = value.into_pyobject(py).unwrap();
+        b.iter(|| {
+            let v: i128 = black_box(&obj).extract().unwrap();
+            black_box(v)
+        });
+    });
+}
+
+fn criterion_benchmark(c: &mut Criterion) {
+    c.bench_function("into_u128_zero", |b| into_u128(b, 0));
+    c.bench_function("into_u128_small", |b| into_u128(b, 42));
+    c.bench_function("into_u128_u32_max", |b| into_u128(b, u32::MAX as u128));
+    c.bench_function("into_u128_u64_max", |b| into_u128(b, u64::MAX as u128));
+    c.bench_function("into_u128_max", |b| into_u128(b, u128::MAX));
+
+    c.bench_function("into_i128_zero", |b| into_i128(b, 0));
+    c.bench_function("into_i128_small_pos", |b| into_i128(b, 42));
+    c.bench_function("into_i128_small_neg", |b| into_i128(b, -42));
+    c.bench_function("into_i128_pos_max", |b| into_i128(b, i128::MAX));
+    c.bench_function("into_i128_neg_min", |b| into_i128(b, i128::MIN));
+
+    c.bench_function("extract_u128_zero", |b| extract_u128(b, 0));
+    c.bench_function("extract_u128_small", |b| extract_u128(b, 42));
+    c.bench_function("extract_u128_u32_max", |b| extract_u128(b, u32::MAX as u128));
+    c.bench_function("extract_u128_u64_max", |b| extract_u128(b, u64::MAX as u128));
+    c.bench_function("extract_u128_max", |b| extract_u128(b, u128::MAX));
+
+    c.bench_function("extract_i128_zero", |b| extract_i128(b, 0));
+    c.bench_function("extract_i128_small_pos", |b| extract_i128(b, 42));
+    c.bench_function("extract_i128_small_neg", |b| extract_i128(b, -42));
+    c.bench_function("extract_i128_pos_max", |b| extract_i128(b, i128::MAX));
+    c.bench_function("extract_i128_neg_min", |b| extract_i128(b, i128::MIN));
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);