Background Acute scrotum is a medical emergency commonly encountered in clinical practice, particularly in pediatric and adolescent populations. It is characterized by sudden onset of scrotal pain and may involve swelling, redness, or tenderness. The most common etiologies include testicular torsion, epididymo-orchitis, trauma, and, less frequently, tumors. Early and accurate diagnosis is critical, especially in cases of testicular torsion, where timely surgical intervention is required to preserve testicular viability. Ultrasound (US), particularly high-resolution gray-scale imaging combined with color Doppler (CD), has emerged as the primary imaging modality for evaluating acute scrotal conditions due to its accessibility, non-invasiveness, and high diagnostic accuracy. Aims and objectives This study aims to assess the diagnostic accuracy of US in differentiating the causes of acute scrotum, specifically focusing on testicular torsion, epididymo-orchitis, and varicocele. We also evaluate its role in reducing unnecessary surgical explorations and improving clinical decision-making in urgent settings. Materials and methods This retrospective observational study was conducted in a tertiary care center in Puducherry, India. A total of 250 male patients, ranging in age from 10 to 70 years, presented with acute scrotal pain over the 12-month study period. Inclusion criteria included all patients with sudden scrotal pain, regardless of clinical suspicion of underlying pathology. US scans were performed using a 7.5- to 12-MHz linear transducer. Gray-scale imaging was used to evaluate the testes, epididymis, spermatic cord, scrotal wall, and inguinal region, while CD was used to assess vascular flow. Statistical analysis was conducted using SPSS Version 18 (IBM Corp., Armonk, NY). Diagnostic accuracy was calculated based on sensitivity, specificity, positive predictive value, and negative predictive value. Results The most common cause of acute scrotum was inflammatory pathology, including epididymo-orchitis, accounting for 56.4% of cases (141 patients). Varicocele was the second most common cause, diagnosed in 11.6% of patients (29 cases), while hernias and epididymal cysts were found in 8% and 7.6% of cases, respectively. Testicular torsion was diagnosed in 2% of cases (five patients). US demonstrated high diagnostic accuracy for inflammatory pathologies, with sensitivity and specificity reaching 97% and 96%, respectively. The sensitivity for testicular torsion was 62%, reflecting the challenges in diagnosing partial or intermittent torsion, while specificity was high at 99%. US's performance in identifying varicocele was excellent, with a sensitivity of 93% and specificity of 98%. Conclusion US, especially when combined with CD, is an indispensable tool in the emergency evaluation of acute scrotum. It provides high diagnostic accuracy for inflammatory pathologies and varicocele while serving as an effective screening modality for testicular torsion. This study reinforces the role of US in reducing unnecessary surgical explorations, guiding clinical management, and improving patient outcomes in urgent clinical settings.