Present study investigates prevalence of diseases, important causes of mortality in Broiler and Layer flocks and their interaction with high altitudes as influenced by different climatic conditions. The basis of data is post mortem examination of the birds submitted to District Diagnostic Laboratory, Department of Animal Husbandry during the period from 2008 to 2011. The total record was 28694 cases, 21896 broilers and 6825 layers. Diagnosis was based on history, clinical signs and post mortem examination. On the basis of altitude District was divided into two categories, below 4000 and above 4000 feet high. Over all Infectious Bursal Disease (IBD) was found most prevalent (29.37%) in broilers followed by Colibacillosis 18.61%, Coccidiosis 17.38% and Chronic Respiratory Disease (CRD) 17.27%, while Coryza 33.75% was most prevalent disease in layers followed by ND 22.12%, CRD 16.11% Coccidiosis 12.48% and Colibacillosis 11.36%. On the basis of altitude, the occurrence of various diseases were IBD 29.22%, Colibacillosis 18.53%, CRD 17.89% and Coccidiosis 17.00% above 4000 feet height in broilers, Coryza 43.92%, CRD 21.91% and ND 17.26% in layers while IBD 32.01%, Colibacillosis 18.78%, Coccidiosis 18.28% and CRD 15.82% in broilers and ND 28.58%, Coccidiosis 20.83%, Coryza 20.25% and Colibacillosis 16.30% in layers below 4000 feet were found. However, rests of the diseases diagnosed during the period were Enteritis, Omphalitis and Hydropericardium.