Varicocele is the most common cause of male infertility. Alpha-glucosidase (α-GLUC) is normal constituent of human semen produced mainly in epididymis and is evaluated as a marker for seminal quality. The aim of this study was to assess seminal α-GLUC in infertile men with varicocele and post varicocelectomy. This study was conducted at Beni-Suef University Hospital. Sixty Egyptian male participants were divided into Group I:  Fertile normozoospermic (n=30) as healthy control, Group II: Infertile oligoasthenoteratozoospermic (OAT) with varicocele (n=30) who underwent varicocelectomy, follow up for 3 months and were classified as Group III:  Infertile OAT post varicocelectomy. Semen analysis was performed manually and seminal α-GLUC was assayed by Enzyme Linked Immunosorbent Assay (ELISA).  Males with varicocele showed statistically significant decrease regarding sperm count, percentage of motile sperms and percentage of normal sperm forms when compared to healthy subjects. Semen parameters showed significant improvement after varicocelectomy. Seminal α-GLUC was statistically significantly higher among fertile normozoospermic men and post varicocelectomy when compared to infertile OAT men. Statistically significant positive correlation was found between α-GLUC level and semen parameters. Moreover, α-GLUC showed sensitivity of (100% and 85%) and specificity of (100%) at cut off values (≤2.67 pg/ml and ≤4.3 pg/ml) between infertile OAT varicocele when compared to fertile normozoospermic and post varicocelectomy men, respectively (p<0.001). In conclusion, seminal α-GLUC could be suggested as marker for judging quality of semen in infertile men with varicocele where varicocelectomy was found to improve α-GLUC level suggesting it to have a role in fertility among men.