Due to increasing international migratory movements, forensic age estimations of living individuals in criminal proceedings are gaining increasing significance for forensic physicians and radiologists involved in delivering expert opinions. The present study examines the suitability of the radiologically well-known Risser sign grading as a possible new criterion in forensic age diagnostics. For this purpose, anteroposterior pelvic radiographs of 643 patients aged between 10 and 30 years were retrospectively evaluated by means of two different Risser sign grading systems (US and French), each with 5 stages. The left and right sides of the pelvis were assessed separately. The data was analyzed with separation of the sexes. Reliable Risser sign determination was possible in 566 cases. In both sexes, stage 4 of both the US and the French grading systems was predominantly first noted at age 14 years. In the US grading system, stage 5 was also first achieved at age 14 years in the majority of both sexes. In the French grading system, females manifested stage 5 at a minimum of 16 years, whereas in males it was first observed at 17 years. As to the nature of iliac crest maturation, interesting deviations were observed at stages 1 and 5, raising doubts about Risser's ossification process. To conclude, both Risser sign grading systems are suitable for forensic age diagnostics, especially to determine whether the 14th year of life has been completed or not. The French Risser sign system additionally allows for statements as to the completion of the 16th year of age.