Compound heterozygosity for CF mutation (F508del or G542X) and CFTR-RD mutation (IVS8-5T) was present in higher frequency among patients with obstructive azoospermia (22.7%), when compared to the fertile controls (0%) p = 3.42×10−5 and all other groups of infertile men: non-obstructive azoospermia/severe oligozoospermia (1.14%, p = 1.16×10−3), azoospermia (0%, p = 3.32×10−4), oligozoospermia (0.92%, p = 4.89×10−4) and normoasthenoteratozoospermia (0%, p = 4.54×10−4). This evidence concerns the gene CFTR and Azoospermia.