Fishes are social organisms and form social groups in some stage of their life cycle. Loose aggregations of fishes forming a social assembly are called shoals. Fish that join with a shoal usually gains a wide variety of benefits. In the present study, the onset of shoaling behaviour in a freshwater fish, Puntius sarana subnasutus was tested using induced breeding technique. In dichotomous choice test, 10-days-old (mean body length = 9 mm) larvae and 20, 30 and 40- days-old juveniles (Mean body length 2.8, 3.1, 4.6 cm respectively) were given the opportunity to swim near shoals of ten fish or a single fish. The larvae on their completion of fin-ray development and start of scale formation to attainment of sexual maturity is said to be juveniles. When introduced into the experimental arena, the larvae as well as the juveniles demonstrated shoaling behavior, swimming near a group of fish rather than a single fish. The fish clearly exhibited an increasing preference to associate with a group corresponding to an increase in their age and the juveniles when become 40-days old, showed little preference for a single fish. The significance of developmental process in shoaling preference of fishes is discussed.