An experiment was conducted to know the influence of sowing date and weather factors on incidence of Alternaria leaf blight of sunflower. The results revealed that during both  years of investigation (1998-99 and 1999-2000) the highest incidence of Alternaria leaf blight was observed in crop sown on first and second fortnight of July and first fortnight of August. Least disease incidence and significantly higher seed yield were obtained when sunflower crop was sown during first and second fortnight of September. Negative correlation between Alternaria leaf blight, mean maximum temperature (-0.55 both years) and yield (-0.13 and -0.64) were observed, while positive correlation was observed with rainfall (0.86 and 0.67) and relative humidity.