Objectives The study aim was to assess rater agreement of the Resistance Training Skills Battery (RTSB) for adolescents. The RTSB provides an assessment of resistance training skill competency and includes six exercises. The RTSB can be used to assess performance and progress in adolescent resistance training programmes and to provide associated feedback to participants. Individual skill scores are based on the number of performance criteria successfully demonstrated and an overall resistance training skill quotient (RTSQ) is created by summing the six skill scores. Design/methods The eight raters had varying experience in movement skill assessment and resistance training and completed a 2–3h training session in how to assess resistance training performance using the RTSB. The raters then completed an assessment on six skills for 12 adolescents (mean age=15.1 years, SD=1.0, six male and six female) in a randomised order. Results Agreement between seven of the eight raters was high (20 of the 21 pairwise correlations were greater than 0.7 and 13 of the 21 were greater than 0.8). Correlations between the eighth rater and each of the other seven raters were generally lower (0.45–0.78). Most variation in the assigned RTSB scores (67%) was between cases, a relatively small amount of the variation (10%) was between raters and the remainder (23%) was between periods within raters. The between-raters coefficient of variation was approximately 5%. Conclusions The RTSB can be used reliably by those with experience in movement skill assessment and resistance training to assess the resistance skill of adolescents.