Physiotherapeutic assessments have to deliver reliable results in order to be acceptable in a clinical and scientific setting. Numerous studies cover the reliability of different 2D posture analysis software, but none has so far examined the reliability of the software Templo 2D when measuring joint angles. The purpose of this prospective, fully-crossed study was to assess the inter- and intrarater reliability of the posture analysis software Templo 2D when measuring the trunk forward lean (TFL). The sample consisted of ten pictures of standing children with a dorsal load of 20% of the body weight. Two female testers, both staff of the University of Applied Sciences, FH Campus Wien, and experienced physiotherapists performed measurements at university premises and repeated the procedure after two weeks. Standardized instruction procedures were carried out before testing. With the obtained data the ICCs of inter- and intrarater reliability and SEMs were calculated, using Spss software. The results showed excellent ICCs of interrater reliability (0.982-0,993) and intrarater reliability (0,986-0,996) and SEMs ranging from 0,39° to 0,70°. The posture analysis software Templo 2D proved to be a highly reliable tool for measuring the TFL in this setting.