Acute scrotal swelling is a potential urologic emergency. There are many conditions which may present with scrotal swelling including spermatic cord torsion, torsion of testicular appendages, epididymitis, orchitis, incarcerated scrotal hernia, hydrocele, varicocele, trauma, tumor and testicular pain in vasculitis syndromes such as Schoenlein-Hennoch purpura. Testicular torsion is the most important condition that must be proven or ruled out to avoid loss of testicular function. History, physical examination and perhaps color-coded doppler-sonography are the tools to diagnose torsion. Using these tools, three diagnostic categories will be defined: Torsion, non-torsion or equivocal diagnosis. In every doubtful case scrotal evaluation is done surgically. Non-torsion is treated according to the different diseases.