Musca domestica Linnaeus or house fly is one of the well-known cosmopolitan pests. Poultry farms, horse stables and ranches are some of the main habitats for house flies to extend their interference and disturbance. Since 1999, large number of fly population around horse stables and barns in Terengganu Equestrian Resort (TER) was detected and still persists till today. Imported horse food are speculated to be the main cause for the increasing number of these flies. The current study was conducted to determine the effect of imported horse food (i.e. chaff, pallet and alfalfa) and the food conditions (wet and dry) on house fly population densities. Commercial sticky papers were used for trapping house fly distribution around the horse stables and barns in TER from October 2013 to January 2014. A total of 36,751 flies were caught during the eight week study period. The highest number of flies (2,843 individuals) was caught when using ‘wet alfalfa + chaff’ whereas the lowest catch was when using ‘dry alfalfa’ (1,652 individuals). Generally, the wet food treatments captured higher flies compared to dry food treatments. The total number of captured flies was found to be influenced by relative humidity. Higher mean number of flies was captured during lower weekly humidity. Our findings conclude that the wet condition of imported horse food in TER increases the house flies population densities. Thus, urgent action should be taken as soon as possible and may need special management considerations in order to reduce the impact of house flies on the horse industry in Malaysia.