Aim The aim of this study is to evaluate sonographic testicular volume of patients who underwent surgical detorsion due to testicular torsion and to reveal the frequency of long-term testicular volume loss and the factors affecting it. Method The files of patients who underwent surgical detorsion due to unilateral testicular torsion in our hospital between 2011 and 2019 were reviewed retrospectively. Age at the time of detorsion surgery, time from the onset of pain to surgery, degree of torsion, and ultrasonographic testicular volumes before detorsion were noted. Afterward, patients with at least 6 months of follow-up were contacted by phone and testicular volumes were measured by scrotal ultrasonography (US). The sonographic formula Length x Width x Height x 0.72 was used to determine testicular volumes. Results There were 97 patients who underwent surgical detorsion within the given time frame. However, 43 of these patients accepted to be involved in the study and a follow-up scrotal US was performed. The mean age at the time of detorsion was 13.6 +/- 5.6 years, whereas it was 16.7 +/- 6.2 years at the time of the follow-up visit. The median time from the onset of pain to surgery was 4 h (range 1-36 h). In the preoperative US, the mean volume of the affected testis was 10.8 +/- 5.6 mm(3), while the mean contralateral testis volume was 10.2 +/- 5.4 mm(3) (p = 0.134). The median follow-up time in our study was 24 months (range 6-96 months). In the control US, the mean volume of the affected testis was 9.5 +/- 7.1 mm(3), while the mean volume of the contralateral testis was 14.4 +/- 9 mm(3) (p = 0.001). The affected testicular volumes decreased in 23 patients (range 1.1-100%), there was no change in testicular volumes in two patients, and there was an increase in testicular volumes in 18 patients (range 3.8-100%). In the ROC analysis, risk of testicular volume loss can be predicted with 87.5% sensitivity and 83.9% specificity when the time from the onset of pain to surgery exceeds 5.5 h (AUC = 0.904). Conclusion Our results indicated that if the time from the onset of pain to surgery exceeds 5.5 h, the testicular volume loss may be expected in the long term. Thus, patients and parents should be informed accordingly.