The authors describe a case of partial monosomy 9p in a newborn infant, with breakpoint in the region p221, due to a father's balanced translocation with karyotype 46 XY t(9;16)(p221;q224). The phenotypical features of our patient reproduce those reported in other 35 cases described up to now in the literature: trigonocephaly, upward slanting palpebral fistures, little and horizontal mouth, disproportionally long fingers and toes. Some peculiar clinical and cytogenetical features of the case are discussed, particularly the early closure of the sternal body ossification centers (already detected during the prenatal life), the partial agenesia of the splenium corporis callosi and the partial anomalous pulmonary venous return. The Authors point out the importance of an early diagnosis, based on the awareness to the clinical abnormalities and dysmorphisms, in order to provide for an adequate and opportune genetic counseling.