A survey on the use of hair oils for hair dressings by the Indian population revealed that mustard oil is preferred by males and coconut oil by females. Amla oil is used equally by both. These oils contain different percentages of various saturated and unsaturated fatty acids which largely determine their toxicity against dermatophytes. For Microsporum canis, M. gypseum and Trichophyton rubrum, amla oil was most toxic, followed by cantharidine and coconut oil, while Trichophyton mentagrophytes was most susceptible to coconut oil followed by amla and cantharidine oil. Mustard oil showed least toxicity to all four test species. The rarity of tinea capitis in India has been concluded to be due to the common use of hair oils by the Indian population.