Individual differences in responsiveness to bitterness were studied among children with and without histories of accidental ingestion of toxic substances. The oral behaviors of 56 children between the ages of 12 and 41 months were videotaped during two minute test periods with lollipops containing different concentrations of bitter sucrose octaacetate (SOA). Videotapes were scored for mouthing times, numbers of oral contacts and latencies to mouthing for each stimulus. Mouthing time was the most sensitive dependent measure examined. Both groups rejected pops with added SOA, decreasing mouthing times as SOA concentration increased. Mouthing times for children with histories of accidental ingestion were slightly lower overall. These results suggest that lowered reactivity to tastes is not a predisposing factor in accidental ingestions, and that bitter substances have some value as deterrents to ingestion for this age group. Rejection of bitter pops by children closely paralleled ratings of bitterness by adult judges.