Scrotal ultrasound, color Doppler and spectral Doppler analysis of intratesticular arteries are the most common and important examinations in boys with scrotal pain. In the existing literature information concerning feasibility and reference values of color Doppler and spectral Doppler in small testes is inconsistent. In the present study 102 boys from 2 days to 16 years old without present or anamnestic scrotal disease were examined in a standardized manner. Using linear scanners (9 - 14 mHz), testicular volumetry and spectral Doppler analysis of typical intratesticular arteries were performed and the paratesticular structures were examined. For analysis we grouped the testes by volume and compared the measured values V. max syst., V. max enddiast., and RI. In all test subjects a complete examination with spectral Doppler analysis of intratesticular arteries could be performed. With increasing testicular volume, there is a linear increase in blood flow velocities V. max syst. and V. enddiast. Irrespective of age and testicular volume, the RI of the intratesticular arteries is 0.54 ± 0.08. In contrast to published data, this study shows that color Doppler and spectral Doppler of testicular arteries can be regularly performed even in small testes of less than 1 ml. Reference values for blood flow velocities and RI were found and should improve the diagnostic value of testicular ultrasound examinations in children.