The current longitudinal study examined students' intentions to quit school as a process that unfolds over time in a social context of upper secondary school. Based on self-report data collected from 1379 students at three time points over 13 months, the results from latent growth curve modelling revealed average increases in intentions to quit school and loneliness among peers at school, and no average change in perceived emotional support from teachers. In line with hypotheses, there was: (1) a negative association between change in perceived emotional support from teachers and change in intentions to quit school; and (2) a positive association between change in loneliness among peers and change in intentions to quit school, while controlling for gender, study track, and previous academic achievement. It is important that schools implement strategies to prioritise the quality of interpersonal relationships as an integral component of their educational mandate.