Two cases of transient neonatal diabetes mellitus associated with anemia, macroglossia and umbilical hernia were studied in relation to the possible etiologies that have been postulated to be responsible for this syndrome. Both patients required insulin therapy for the control of their hyperglycemia but case number two needed to be treated for 14 months before glucose normalization occurred. This patient developed classical insulin dependent diabetes mellitus during our follow-up; the HLA typing showed DR4 allele.