Résumé : Whey hydrolysate formulas are a recent and important innovation in infant feeding. This study compared clinical tolerance and acceptability of a whey hydrolysate formula (WH) with those of a whey-predominant formula (WF) in 45 infants. Four infants (16%) who refused to drink WH formula were eliminated from the study. Mean volume intake was significantly lower for WH (120 mL/kg/day) than for WF (147 mL/kg/day; P <.001). Consequently, mean caloric intake was also significantly different: 80 kcal/kg/day (WF) vs 97 kcal/kg/day (WF; P <.001). Nevertheless, weight gain from birth to 13 weeks of age was nearly identical in both groups (171% for WH vs 178% for WF). No significant differences were noted in duration of feeding, number of pauses during feeding, number of stools per day, or number of regurgitations per day. The lower rate of caloric intake and the dropout rate of 16% for WH raise questions about the use of WH formula in normal infants, as has become the case in some Western European regions. © 1993, Sage Publications. All rights reserved.