Aim: The present study evaluated the effect of differences in the peak systolic velocity (PSV) and resistive index (RI) in the testicular artery (TA), capsular artery (CA), and intratesticular artery (ITA) after microscopic subinguinal varicocelectomy (MSV) on postoperative pain and semen parameters. Patients and methods: Scrotal color Doppler ultrasound (CDUS) measurements were made in 33 patients (age 18-31 years) prior to MSV and 3 and 6 months after MSV. Pain was recorded using a visual analog scale and sperm concentration was determined to analyze the predictive value of the CDUS parameters regarding surgical outcome. Results: A significant decrease in pain scores was observed in most patients at both follow-ups. The first postoperative CDUS revealed a significant increase in the TA-PSV (p < 0.001) and a decrease in the TA-RI (p=0.002) and CARI (p=0.006). The second postoperative CDUS also revealed a significant increase in the TA-PSV and a decrease in the TA-RI, and the PSV in the ITA and CA and RI in the ITA and CA were significantly different from the values obtained pre-operatively and at the first follow-up. A negative correlation was found between the pain level and TA-PSV (r=-0.433, p=0.012), whereas sperm concentration positively correlated with both the TA-PSV and CA-PSV (r=0.534, p=0.001 and r=0.455, p=0.008, respectively). Conclusions: The PSV and RI are useful parameters for detecting changes in testicular microhemodynamics after MSV. In addition, the TA-PSV and CA-PSV can be used to predict improvements in pain and sperm concentration.