This study was investigated whether parental consanguinity in males has an effect on or relationship with some infertile subgroups and some semen and hormone parameters. The charts of 2651 infertile males were evaluated retrospectively for parental consanguinity ratios, sperm counts, motility parameters and hormonal values from the records of 2651 infertile males. In 1260 eligible males the first cousin parental consanguinity ratio was 22.6%. In 119 males with nonobstructive azoospermic (NOA) and 430 males with normal sperm counts, the ratios were 34.5% and 20.9%, respectively (p = 0.002). In the NOA group the parental consanguinity ratios were 27.1% (23/85) and 52.9% (18/34) in males with FSH values of >7.6 and <7.6 mIU/ml, respectively (p = 0.007). In males with normal sperm counts if the parents were first cousins, both sperm counts and motility parameters were significantly reduced when compared with the others. To our knowledge, this is the first study of consanguinity ratios among some infertile subgroups. In males with parental consanguinity lower sperm counts and motility ratios in normozoospermic males and lower FSH levels in the NOA group might show a relation with some genetically transmitted defects.