The production of extracellular lipolytic enzymes by 2 strains of Aspergillus aculearus associated with the deterioration of peanuts and a marketed margarine in Nigeria and the effects of temperature and pH on the activities of the enzymes were investigated. Lipolytic enzymes were detected within 2 days of incubation at 35 °C in 4 out of 6 natural oils and in 3 out of 4 synthetic glycerides used irrespective of strain type. The lipolytic enzymes of both strains hydrolysed both natural oils and synthetic glycerides to free fatty acids. There was correlation between the mycelium produced to the quantity of free fatty acids produced in medium within the first 8 days of incubation. There was a general increase in mycelium production with increase in incubation period. The enzyme activities were at peak at 30-35 °C and at pH 6-7.