Egg is a major source of dietary cholesterol. Previous studies on the effect of egg on serum lipid profile have given conflicting results. Further, the serum lipid response to egg shows marked individual variation. Since the variation is at least partly genetically determined, and the response depends partly on the overall diet, studies on different ethnic groups are important. There is hardly any study on the subject available on Indians. In the present investigation, eighteen healthy young volunteers (7 male, 11 female) on a lacto-vegetarian diet were given one boiled egg per day for 8 wk in a randomized controlled cross-over study. Compared to the values obtained after 8 wk of egg-free period, the mean serum total cholesterol, LDL cholesterol, HDL cholesterol, total cholesterol/HDL ratio, VLDL cholesterol and triglycerides were not significantly different after 8 wk of egg consumption. However, the serum total cholesterol after 4 wk of egg consumption was significantly higher than the control values. Further, seven subjects out of 18 had an appreciable elevation of serum total cholesterol or LDL cholesterol, or both, after 8 wk of egg consumption. The study suggests that in young healthy Indian subjects on a vegetarian diet, consuming one egg per day raises serum cholesterol levels at 4 wk but in the majority baseline values are restored by 8 wk. However, some hyper-responders continue to have elevated serum cholesterol even at 8 wk. Knowing the response of an individual may be important before making egg consumption a regular habit.