Five fungicides, 2 antibiotics and 2 combinations of fungicides and antibiotics were evaluated against incidence of bacterial and fungal diseases ofPiper betleL. Cv. ‘Desawari’. Copper oxychloride 50 WP (Blitox‐50) at 0.25% at 15 days interval was most effective against mortality caused byPhytophthora parasiticavar.piperinaDastur; whereas 0.25% Copper oxychloride 50 WP with 500 ppm streptocycline was best against leaf spots caused byXanthomonas campestrispv.betlicolaDye. andColletotrichum capsiciSyd. (Butler & Bisby). Other formulations viz., Carbendazim (Bavistin), Trideomorph (Calixin), Mancozeb (DithaneM‐45), Copper oxychloride 50 WP (Kilex), Paushamycin and Streptocycline were only next to the copper oxychloride 50 WP (Blitox‐50) or its combination with streptocycline.