A total of 186 infants, suffering from acute diarrhea were studied and divided into two groups: 84 children were placed in group A and given the ORS recommended by the World Health Organization which contains sodium and glucose at concentrations of 60 and 90 mmol/L respectively and an osmolality of 311 mOsm/kg (mmol/kg) (ORS-90). Group B included 82 children who received an ORS containing sodium and glucose at concentrations of 60 and 90 mmol/L respectively and with an osmolality of 240 mOsm/kg (mmol/kg) (ORS-60). Seven belonging to group A (8.3%) required intravenous rehydration due to the severity of the diarrhea (three cases), persistent vomiting (three cases) and paralytic ileus (one case), while only two cases belonging to group B (2.5%) required intravenous rehydration due to severe losses through feces (one case) and another due to paralytic ileus (one case). No differences were observed due to the variations in sodium concentrations among either of the groups of patients, whether that be in the natremias when admitted or once rehydrated, with a general tendency towards the correction of the hypernatremia or hyponatremia seen during admittance with both types of ORS. A similar situation was observed with the variations in serum potassium. The results obtained from this study show the different advantages of using an ORS with lesser sodium and glucose concentrations as well as minor osmolality with those from using the solution recommended by the World Health Organization, when a lesser index of failures is observed in the treatment of children with acute diarrhea with oral rehydration therapy. Yet before widely recommending its' use, it should be demonstrated that the new ORS induces lesser losses through feces during the rehydrating period in children dehydrated due to acute diarrhea.