Yildiz, M. and Ekiz, H. 2014. The effect of sodium hypochlorite solutions on in vitro seedling growth and regeneration capacity of sainfoin (Onobrychis viciifolia Scop.) hypocotyl explants. Can. J. Plant Sci. 94: 1161-1164. The aim of the present study was to determine the effects of different concentrations (1, 2, 3, 4 and 5%) and temperatures (10, 20 and 30°C) of sodium hypochlorite (NaOCl) solutions on in vitro seed germination, seedling growth and regeneration capacity of sainfoin (Onobrychis viciifolia Scop.) hypocotyl explants. All parameters were negatively affected by concentrations of NaOCl over 2% and temperatures over 20°C while the best results were obtained when seeds were surface-sterilized with 2% NaOCl at 20°C for 30 min. following a pretreatment with 95% ethanol.