The flight activity and the population fluctuations of broad bean leaf miner, Uriomyza trifolii (Burgess) were investigated throughout the growing season of broad bean Vicia faba L. by using yellow sticky traps at Qualiubia governorate in 2001 and 2002 seasons. Traps were positioned at five different heights above the ground; 25, 50, 75, 100 and 125 cm. The yellow sticky trap was an effective tool for monitoring the adults of L. trifalii. Yellow traps placed 25 cm above the ground caught significantly more adults than the other trap heights overall the growing season. Thus, this leaf miner has a limited vertical range of flight activity. The correlation between trap < /p> heights and the number of adults trapped was negative. The males and females were equally responsive to yellow traps at any height. in both seasons, the highest number of seized aduits occurred in February and March, while, the lowest adult populations were obtained in April. Two peaks for L tn'for'ii adults on broad bean season were recorded.