This review focuses on selected areas implicated in male infertility including: (i) autosomal and sex chromosomal abnormalities; (ii) genetic disorders associated with impaired gonadotrophin secretion or action; (iii) microdeletions within regions of the Y-chromosome containing candidate gene families for spermatogenesis; (iv) the genetic nexus between cystic fibrosis and congenital bilateral absence of the vas deferens; and (v) insights into human infertility as gleaned from animal studies into mechanisms involving the Bcl-2 family of apoptosis regulators and the interaction between the c-kit encoded tyrosine kinase receptor and its ligand, stem cell factor.