diff --git a/Cargo.lock b/Cargo.lock
index e6db56ce30..b2a252c97f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3562,6 +3562,7 @@ dependencies = [
  "strum",
  "tempfile",
  "tokio",
+ "tracing",
  "typed-builder",
  "typetag",
  "url",
diff --git a/crates/iceberg/Cargo.toml b/crates/iceberg/Cargo.toml
index 159a7da7f2..9353a31842 100644
--- a/crates/iceberg/Cargo.toml
+++ b/crates/iceberg/Cargo.toml
@@ -75,6 +75,7 @@ serde_repr = { workspace = true }
 serde_with = { workspace = true }
 strum = { workspace = true, features = ["derive"] }
 tokio = { workspace = true, optional = false }
+tracing = { workspace = true }
 typed-builder = { workspace = true }
 typetag = { workspace = true }
 url = { workspace = true }
diff --git a/crates/iceberg/src/util/mod.rs b/crates/iceberg/src/util/mod.rs
index 28eda66d49..3cf2eef9b0 100644
--- a/crates/iceberg/src/util/mod.rs
+++ b/crates/iceberg/src/util/mod.rs
@@ -35,11 +35,11 @@ const DEFAULT_PARALLELISM: usize = 1;
 /// parallelism can change during the lifetime of an executing
 /// process, but this should not be called in a hot loop.
 pub(crate) fn available_parallelism() -> NonZeroUsize {
-    std::thread::available_parallelism().unwrap_or_else(|_err| {
-        // Failed to get the level of parallelism.
-        // TODO: log/trace when this fallback occurs.
-
-        // Using a default value.
+    std::thread::available_parallelism().unwrap_or_else(|err| {
+        tracing::warn!(
+            error = %err,
+            "Failed to determine available parallelism; falling back to {DEFAULT_PARALLELISM}",
+        );
         NonZeroUsize::new(DEFAULT_PARALLELISM).unwrap()
     })
 }