diff --git a/scripts/profile.sh b/scripts/profile.sh
new file mode 100755
index 0000000..95fbad2
--- /dev/null
+++ b/scripts/profile.sh
@@ -0,0 +1,158 @@
+#!/bin/bash
+
+# Profile bench.py using NVIDIA Nsight Systems (GPU-only mode)
+#
+# Usage:
+#   bash scripts/profile.sh [options]
+#
+# Options:
+#   --max-len LENGTH     Max sequence length (default: 32768)
+#   --policy POLICY      Sparse policy: full, xattn (default: xattn)
+#   --gpu GPU_ID         GPU to use (default: 0)
+#   --gpu-util UTIL      GPU memory utilization (default: 0.9)
+#   --input-len LENGTH   Input length (default: max-len - 1)
+#   --bench-decode       Run decode benchmark instead of prefill
+#
+# Output:
+#   results/nsys/bench_<policy>_<max_len>_<timestamp>.nsys-rep
+#
+# Examples:
+#   bash scripts/profile.sh
+#   bash scripts/profile.sh --max-len 65536 --gpu-util 0.7
+#   bash scripts/profile.sh --policy full --max-len 32768
+#   bash scripts/profile.sh --bench-decode
+
+set -e
+
+# Default configuration
+MAX_LEN="32768"
+POLICY="xattn"
+GPU_ID="0"
+GPU_UTIL="0.9"
+INPUT_LEN=""
+BENCH_MODE="prefill"
+
+# Parse arguments
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --max-len)
+            MAX_LEN="$2"
+            shift 2
+            ;;
+        --policy)
+            POLICY="$2"
+            shift 2
+            ;;
+        --gpu)
+            GPU_ID="$2"
+            shift 2
+            ;;
+        --gpu-util)
+            GPU_UTIL="$2"
+            shift 2
+            ;;
+        --input-len)
+            INPUT_LEN="$2"
+            shift 2
+            ;;
+        --bench-decode)
+            BENCH_MODE="decode"
+            shift
+            ;;
+        -h|--help)
+            echo "Usage: $0 [options]"
+            echo ""
+            echo "Options:"
+            echo "  --max-len LENGTH     Max sequence length (default: 32768)"
+            echo "  --policy POLICY      Sparse policy: full, xattn (default: xattn)"
+            echo "  --gpu GPU_ID         GPU to use (default: 0)"
+            echo "  --gpu-util UTIL      GPU memory utilization (default: 0.9)"
+            echo "  --input-len LENGTH   Input length (default: max-len - 1)"
+            echo "  --bench-decode       Run decode benchmark instead of prefill"
+            exit 0
+            ;;
+        *)
+            echo "Unknown option: $1"
+            exit 1
+            ;;
+    esac
+done
+
+# Path configuration
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
+OUTPUT_DIR="$PROJECT_ROOT/results/nsys"
+BENCH_SCRIPT="$PROJECT_ROOT/bench.py"
+
+# Create output directory if needed
+mkdir -p "$OUTPUT_DIR"
+
+# Generate timestamp for unique filename
+TIMESTAMP=$(date +%Y%m%d_%H%M%S)
+
+# Convert max_len to human-readable format (e.g., 32768 -> 32k)
+if [ "$MAX_LEN" -ge 1024 ]; then
+    MAX_LEN_SUFFIX="$((MAX_LEN / 1024))k"
+else
+    MAX_LEN_SUFFIX="${MAX_LEN}"
+fi
+
+OUTPUT_FILE="$OUTPUT_DIR/bench_${POLICY}_${MAX_LEN_SUFFIX}_${BENCH_MODE}_${TIMESTAMP}"
+
+# Build bench.py arguments
+BENCH_ARGS="--max-len $MAX_LEN --gpu-util $GPU_UTIL"
+
+if [ -n "$POLICY" ]; then
+    BENCH_ARGS="$BENCH_ARGS --policy $POLICY"
+fi
+
+if [ -n "$INPUT_LEN" ]; then
+    BENCH_ARGS="$BENCH_ARGS --input-len $INPUT_LEN"
+fi
+
+if [ "$BENCH_MODE" = "decode" ]; then
+    BENCH_ARGS="$BENCH_ARGS --bench-decode"
+fi
+
+echo "============================================================"
+echo "NVIDIA Nsight Systems Profiling (GPU-only)"
+echo "============================================================"
+echo "Bench script: $BENCH_SCRIPT"
+echo "Policy:       $POLICY"
+echo "Max length:   $MAX_LEN"
+echo "GPU:          $GPU_ID"
+echo "GPU util:     $GPU_UTIL"
+echo "Bench mode:   $BENCH_MODE"
+echo "Output file:  $OUTPUT_FILE.nsys-rep"
+echo ""
+
+# nsys profile options:
+# --trace=cuda,nvtx : Trace CUDA API and NVTX markers
+# --force-overwrite=true : Overwrite existing output file
+# --output=<path> : Output file path (without .nsys-rep extension)
+
+echo "Running nsys profile..."
+echo "Command: python bench.py $BENCH_ARGS"
+echo ""
+
+CUDA_VISIBLE_DEVICES=$GPU_ID PYTHONPATH="$PROJECT_ROOT:$PYTHONPATH" \
+nsys profile \
+    --trace=cuda,nvtx \
+    --force-overwrite=true \
+    --output="$OUTPUT_FILE" \
+    python "$BENCH_SCRIPT" $BENCH_ARGS
+
+echo ""
+echo "============================================================"
+echo "Profiling completed successfully!"
+echo "============================================================"
+echo "Output file: $OUTPUT_FILE.nsys-rep"
+echo ""
+echo "To view results in GUI:"
+echo "  nsight-sys $OUTPUT_FILE.nsys-rep"
+echo ""
+echo "To export statistics:"
+echo "  nsys stats --report cuda_api_sum $OUTPUT_FILE.nsys-rep"
+echo "  nsys stats --report cuda_gpu_kern_sum $OUTPUT_FILE.nsys-rep"
+echo "  nsys stats --report cuda_gpu_mem_size_sum $OUTPUT_FILE.nsys-rep"
+echo "============================================================"