Late blight of potato, caused by Phytophthora infestans (Mont.) de Bary, is one of the most important diseases of potato (Solanum tuberosum L.) in all potato growing areas of Pakistan. Field experiments were conducted to screen out thirty potato varieties and to evaluate the efficacy of three fungicides namely Tazoline (mancozeb + metalaxy), Kocide (copper oxychloride) and Ridomil Gold (mefenoxam) on three most susceptible potato varieties against late blight. Most of the potato varieties showed susceptibility to P. infestans. None of the variety was found immune or resistant. Fourteen varieties were moderately resistant, eight were moderately susceptible, five were susceptible and three were highly susceptible. In case of fungicide effect Ridomil Gold (DI 44%) showed the best results followed by Tazoline (60%) and Kocide (73%) as compared to control (82%). Variety SH-479 gave the highest potato yield (217.7 g) per plant followed by SH-332 (194.3 g) as compared to control treatment (124.7 g).