Hounslow Police said the incident took place in Lampton Park.
Officers said an altercation happened in broad daylight between two men inside the park grounds during which an assault took place.
The incident happened over the Easter weekend on Saturday (April 15) at around 4pm.
No further information on the assault has been released by the police.
Police are now urging anyone who may have seen what happened to come forward and assist their enquiries.
Hounslow MPS said in a tweet: "Did you witness assault in Lampton Park on Saturday 15/4 at 4pm? Can you help? Call our CID on 0208 247 6246 ref 0507843/17."
Anyone who can help police with their enquiries should call the CID team on 0208 247 6246 and quote reference number 0507843/17.
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