The growth and hemolysin production of Vibrio cholerae non-O1 was investigated under various pH and nutritional conditions. Addition of glucose or di-sodium hydrogenphosphate (Na2HPO4) into heart infusion (HI) broth significantly affected the growth and hemolysin production. Ten strains of V. cholerae non-O1 tested exhibited four groups in their behavior in growth and hemolysin production in the presence of glucose. These groups were: inhibition, suppression, promotion and no alteration in their growth and hemolysin production. Di-sodium hydrogenphosphate enhanced hemolysin production in five strains and caused suppression in one strain (CO-21). Four strains were not affected by the addition of this chemical. The influence of pH on the growth and hemolysin production was also investigated. The growth of four strains was inhibited at pH 6 but showed good growth at pH 7 and 8. Six strains were capable of growing at wide pH range (6 to 8). Three strains had their optimum pH for hemolysin production at 6 while the others had their optimum pH at 7 and 8.