Background: Shear wave elastography (SWE) is extensively used in testicular pathology evaluation. Varicocele subfertility complex associated with testicular fibrosis. Unilateral varicocele is not uncommon association in male infertility. The aim of the present study is answering the question, why unilateral varicocele are fertile while others are not, despite contralateral apparently normal testis? Patients and methods: A case control study was carried out on 48 patients diagnosed with unilateral varicocele and abnormal spermogram. Patients were collected from our urology outpatient clinics of Zagazig University Hospitals, in the period between March and December 2019. A total 10 volunteers with unilateral varicocele and normal semen parameters participate to know baseline SWE figures. Results: In the case group, the mean age was 33.83 (SD 5) years. Mean sperm count, motility and normal forms among the studied patients was 6.76 (SD 2.4 million/ml), 17.656 (SD 3.35) and 7.01 (SD 1.76) %, respectively with a negative correlation with contralateral testicular stiffness.Mean value of the apparently normal contralateral testicular stiffness was significantly higher than in control group as their mean results were 3.63 (SD 0.79) and 1.43 (SD 0.25) kpasc, respectively. During our cases SWE mapping, ipsilateral testis stiffness SWE mean value was 4.81 (SD 1.03) kpasc and insignificantly higher than control. Conclusion: SWE data of normally apparent contralateral testis of unilateral varicocele patients with abnormal semen parameters could reveal stiffer parenchyma that may reflect the presence of a harmful insult to the testis. Thus, it could add a warning sign for surgeon to interfere in these unilateral cases, even with euspermic pattern and varicosities.