The study aims to examine longitudinal trajectories of Post Traumatic Growth (PTG) during the COVID-19 pandemic in a sample of 190 (54.70% female) early adolescents with a mean age of 11.34 years (SD = 0.82). The influence of the time-invariant predictor - resilience traits - and time-varying covariates - COVID-19 related stress and systems life satisfaction - on the trajectories was further examined. The latent growth curve analysis showed a significant negative slope, suggesting a linear decline in PTG over time. Pre-pandemic time-invariant predictors did not explain inter-individual variability in PTG, whereas time-varying covariates were significantly associated with short-term PTG variations. In particular, adolescents with higher levels of COVID-19-related stress reported significantly higher PTG scores at each time point, with the effect gradually decreasing over the three waves. In parallel, systems life satisfaction was significantly associated with higher PTG. The findings support the idea of PTG as a potential coping strategy in response to stressful situations and highlight the critical role of stress and systems life resources in triggering growth after a stressful life event.