The diagnosis of holoprosencephaly usually implies a poor prognosis and is often regarded as a contraindication for surgical correction of associated clefts of the lip or palate. Between 1985 and 1991, 4 patients with lobar holoprosencephaly were evaluated and studied with computed tomography or magnetic resonance imaging. All had cleft palate and 3 had paramedian cleft lip; all 4 exhibited some degree of nasal dysplasia. All patients are presently alive, at a mean age of 26.6 +/- 2.4 months (mean +/- SD). Three of the children showed normal or near normal development, whereas the fourth was severely retarded. Our experience suggests that some children with lobar holoprosencephaly have a highly variable degree of intellectual development and that long-term survival may be expected.