Yield loss assessment studies were carried out in Madenur,Hassan and Beekanahalli, Chikmagalur during 2004 and 2005 on potato pests. Aphids, Myzus persicae caused on an average 6 per cent loss in yield at Madenur and 3 per cent loss in Beekanahalli. The yield loss due to Spodoptera litura was 8 per cent at Madenur and 4 per cent at Beekanahalli. The yield loss due topotato tuber moth, Phthoremaea operculella was 9 per cent at Madenur while it was 6 per cent at Beekanahalli. The yield loss due to mite, Polyphagotarsonemus latus was 26.80 per cent at Madenur and it was 4 per cent at Beekanahalli.