The department received a call reporting the fire from a neighbor in the adjacent lot just after 12:30 p.m.
An off duty Chatham firefighter arrived on scene first to find the camper engulfed in flames with several propane tanks threatened.
Harwich firefighters extinguished the fire within 10 minutes of arriving, but remained on scene for almost 45 minutes to make sure the fire was completely put out.
The trailer was not occupied and there were no injuries reported.
The owner of the camper removed several birds from the trailer before the fire department arrived.