We report two cases of interstitial deletion of the short arm of chromosome 1. The first was a 10 year old boy whose karyotype was 46,XY,del(1) (p22.1p31.2); the second was a 6 month old boy with a chromosome complement of 46,XY,del(1) (p22.3p31.3). A number of the malformations observed were common to both cases. There has been one previously reported case with the same breakpoints as our case 1 and a phenotype that was strikingly similar.