diff --git a/python/sglang/srt/layers/attention/aiter_backend.py b/python/sglang/srt/layers/attention/aiter_backend.py
index ec492bb4d..e8a63e8bb 100755
--- a/python/sglang/srt/layers/attention/aiter_backend.py
+++ b/python/sglang/srt/layers/attention/aiter_backend.py
@@ -43,6 +43,7 @@ if TYPE_CHECKING:
 
 try:
     from aiter import (
+        flash_attn_varlen_fp8_pertensor_func,
         flash_attn_varlen_func,
         get_mla_metadata_info_v1,
         get_mla_metadata_v1,
@@ -2337,6 +2338,43 @@ class AiterAttnBackend(AttentionBackend):
             if layer.sliding_window_size is not None and layer.sliding_window_size > -1:
                 window_size = (layer.sliding_window_size, -1)
 
+            if (
+                get_bool_env_var("SGLANG_AITER_FMHA_FP8_ASM", "False")
+                and is_gfx95_supported()
+                and forward_batch.forward_mode.is_extend()
+                and forward_batch.extend_prefix_lens_cpu is not None
+                and not any(forward_batch.extend_prefix_lens_cpu)
+                and window_size == (-1, -1)
+                and sinks is None
+                and self.logits_soft_cap == 0.0
+                and layer.qk_head_dim == 256
+                and layer.v_head_dim == 256
+                and self.kv_cache_dtype == fp8_dtype
+            ):
+                q_c = q.contiguous().view(-1, layer.tp_q_head_num, layer.head_dim)
+                k_c = k.contiguous().view(-1, layer.tp_k_head_num, layer.head_dim)
+                v_c = v.contiguous().view(-1, layer.tp_v_head_num, layer.v_head_dim)
+                fp8_q_descale = (
+                    layer.k_scale if layer.k_scale is not None else self.k_scale
+                )
+                o = flash_attn_varlen_fp8_pertensor_func(
+                    q_c.to(fp8_dtype),
+                    k_c.to(fp8_dtype),
+                    v_c.to(fp8_dtype),
+                    fp8_q_descale,
+                    k_descale,
+                    v_descale,
+                    self.qo_indptr[:bs0],
+                    self.qo_indptr[:bs0],
+                    self.forward_metadata.max_q_len,
+                    self.forward_metadata.max_q_len,
+                    softmax_scale=layer.scaling,
+                    causal=True,
+                )
+                if o.dtype != self.input_dtype:
+                    o = o.to(self.input_dtype)
+                return o.view(-1, layer.tp_q_head_num * layer.head_dim)
+
             if self.kv_cache_is_vectorized_5d:
                 return forward_extend_vectorized_5d(
                     self,