The activity of Alcohol dehydrogenase (ADH), its isozyme profile and aldehyde level were studied in oneweek- old submerged seedlings of four rice cultivars viz., FR13A, Gangasiuli (submergence tolerant); Mahsuri and Sarala (susceptible to submergence). ADH actvity increased under submergence and attained peak value after 48h of stress in all the varieties. Seedlings of the susceptible cultivar, Mahsuri exhibited maximum induction of ADH activity together with least rise in aldehyde content indicating that ADH activity alone may not be the sole determinant of submergence tolerance in all varieties of rice. Only one ADH isozyme was observed in the seedlings which was highly induced in all cultivars under submergence.