Testicular size is an important parameter to investigate male reproductive and sexual functions. However, diagnosis and treatments are hindered by the lack of country-specific standard values for testicular volume. We conducted the present retrospective chart review study on 24,440 men who sought consultation at Andrology and Sexual Medicine—Hanoi Medical University Hospital to provide a reference range of testicular volume and to determine the correlations between testicular volume, age and hormonal profiles. These men were classified into groups being healthy fathers, hypogonadal men, unexplained infertile men, men with unknown fertility, testicular pathologies and other andrological condition groups. Hypogonadal men and unexplained infertile men had significantly smaller testicular sizes compared with healthy fathers. The mean value of testicular volume of healthy subjects was 13.64 ± 3.44 ml (left testis: 13.94 ± 3.72 ml; right testis: 13.34 ± 3.61 ml; p < 0.001). Testicular size of Vietnamese men was negatively correlated with LH and FSH (Rho = −0.16 and −0.33, p < 0.001) and positively correlated with testosterone after adjusting for confounding factors. Testicular volume was independent of the subject's age and smoking habits.