Received June 18, 2019
Accepted December 18, 2019

Objective: Undescended testis (UDT) is a urogenital disease with infertility consequence. We evaluated the cytogenetic abnormalities in Iranian infertile UDT patients which have not been described before. Methods: This study was conducted on 522 infertile UDT patients as case group and two control groups, one with 300 infertile men without UDT and another with 268 fertile men. Results: Chromosomal alterations were found in 45 cases of UDT (8.62%). Seven of the alterations were considered as normal features. Klinefelter and mosaicism were the most common anomalies among the patients. Chromosomal alterations were found in 31 infertile men of the control group (10.33%) which 13 patients had normal variations and 18 (6%) had abnormalities. Furthermore, nine alterations were found in the second fertile control group (3.35%), six of them had normal variations and three of them (1.11%) had chromosomal abnormalities. Conclusion: Despite the high rate of abnormalities in the infertile control group (6%), it is concluded that UDT is associated with abnormal karyotypes in Iranian population due to the higher rate than the general population which should be within 0.7-1%. The incidence of abnormal karyotypes will be increased when the infertile patients have other severe defects such as UDT disease.