Background: Cycle skills training (CST) in a traffic free and light traffic environment is a promising approach to improve children’s cycling-related skills and knowledge. This study examined the effects of short-term CST on children’s cycling-related knowledge, confidence and behaviours. Methods: Children (n = 429; 11.0 +/- 0.9 years; 52.1% boys; 3 schools) participated in either playground-based CST (Traffic-Free CST; n = 164) or playground-based plus on-road CST (Traffic-Free+OnRoad CST; n = 265) in Dunedin, New Zealand in 2015-2016. Children completed pre-training and post-training surveys and practical skills assessment. Data were analysed using McNemar tests and paired t-tests. Results: At baseline, 36.6% of children cycled >= 1/week, 7.7% cycled to school and 40.3% preferred cycling to school. Both types of CST significantly improved children’s cycling-related knowledge (Traffic-Free: 80.8 +/- 10.8% to 90.8 +/- 10.3%; Traffic-Free+OnRoad: 84.2 +/- 9.4% to 95.0 +/- 5.9%; both p< 0.001) and self-perceived confidence to cycle in the parks/playgrounds (Traffic-Free: 61.3% to 74.8%, p = 0.001; Traffic-Free+OnRoad: 81.1% to 90.6%, p< 0.001) and on the road (Traffic-Free: 25.3% to 38.8%, p = 0.010; Traffic-Free+OnRoad: 51.7% to 67.4%, p< 0.001) but not to school (Traffic-Free: 46.9% to 50.5%, p = 0.791; Traffic-Free + OnRoad: 72.1% to 70.3%, p = 0.029). Cycling habits and preferences did not change significantly after CST with the exception of increased rate of cycling to school after Traffic-Free + OnRoad CST (10.6% to 12.5%). Conclusion: CST with or without on-road training improved children's cycling-related knowledge, and self-perceived confidence to cycle on playgrounds and on the road but not to school. Traffic-Free+OnRoad CST had positive but small effects on increasing cycling to school. Additional interventions targeting parents, schools and built environment changes may be necessary for behavioural change.