Abstract: Fifteen advanced lines of tomato including two check cvs. `Manik` and `BARI-10` were assessed under natural epiphytotics for their performance to late blight (Phytophthora infestans) and early blight (Alternaria solani). The highest late blight disease incidence was found in V-52 & V-215 and the lowest in V-378. Two lines were found resistant (V-426 & V-259), two moderately resistant (V-187 & V-385), two were tolerant (V-282 & V-422), four moderately susceptible (V-378, V-138, V-258 and BARI 10), three were susceptible (V-330, V-201 and Manik) and two highly susceptible (V-52 & V-215), but none was found highly resistant. In case of early blight V-259 showed the highest and V-215 showed the lowest disease incidence. On the basis of early blight disease intensity, one was found resistant (V-52), three were moderately resistant (V-138, V-201 and V-215), six were moderately susceptible (V-378, V-282, V-330, V-426, V-422 and Manik), four were susceptible (V-187, V-385, V-258 and BARI 10), one was highly susceptible (V-259) and none was found highly resistant.