A Triple-Exponential extreme value distributlon based on Polsson assumption and Adler-Lomnitz and Lomnitz’s (1978, 1979) magnitude-frequency relation has been applied to the annual maximum earthquake magnitudes in the northwest Himalayan region (Lat. 710-820 E and Long. 280-380 N) and the results have been compared with those from commonly used Gumbel’s distribution and Extreme Value type-IIl distributian. Maximum magnitudes for different return perlods evaluated from Triple-Exponential distribution show lesser dispersion compared to the results from other extrems value distributlon, and hence this diatribution may be surmised to be better. The results from the Log-Pearson Type-Iil distribution, which is very commonly used for the flood data, has bean also found to be in excellent agreement with those from Triple Exponential Distributlon. From the Triple – exponential distribution for northwest Indlan region, probability of occurrence of different magditudes has been plotted as a function of return perlod, This may be useful to find the design earthquake magnitude during a given life period with any deslred contidence level.