Background Distal forearm fractures are common in children. The reference standard to diagnose these fractures is by conventional radiography, which exposes these patients to harmful radiation. Ultrasound (US) seems to be a good alternative. However, emergency physicians (EPs) in the Netherlands have limited experience in using US for diagnosing fractures in children. Objective The primary objective was to determine the accuracy of US, performed by a Dutch EP, compared with conventional radiography, in diagnosing distal forearm fractures in children. As a secondary objective, differences in pain scores during the performance of both US and plain radiography were determined. Methods Children, aged between 0 and 14 years old, suspected of having a distal forearm fracture were enrolled at the Emergency Department. US and radiographic findings were compared. Statistics for accuracy were calculated. Pain scores were recorded during US and radiography and compared as well. All participating operators received an hour-long pretrial training. Results 100 patients were enrolled. The mean age was 9.5 years (SD, 3.6), and 50% were women. Overall diagnostic accuracy was 92% (95% CI 85%-96%). The sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios for US were 95% (95% CI 87% to 99%), 86% (95% CI 71% to 95%), 92% (95% CI 83% to 97%), 91% (95% CI 76% to 98%), 6.86 (95% CI 3.04 to 15.51) and 0.05 (95% CI 0.02 to 0.17), respectively. The pain scores during US and radiographic imaging were 3.3 and 4.6, respectively (p<0.01). Conclusions In this study, we showed that US is an accurate method for diagnosing distal forearm fractures in children. The main advantages are that it is radiation-free and rapidly practicable, and that patients experience it as less painful than radiography. Moreover, this study has proven that with minimal experience in US, good diagnostic accuracy can be achieved after brief training.