Physical educators have a responsibility to create a learning environment that is viewed as supportive of students' psychological needs and which helps reduce amotivation. The aim of the current study was to examine the effects of students' perceived need support on four dimensions of amotivation in physical education (PE) ("deficiency in ability beliefs", "deficiency in effort beliefs", "insufficient task values and unappealing task characteristics"). A longitudinal design was employed with three assessment points over a 6-week unit of work in cricket. Surveys were conducted with 162 boys (mean age = 14 years, SD = 0.87) over three consecutive PE lessons in weeks one, three and five. At the start of the study, multilevel modelling analyses showed all three types of perceived need support negatively predicted "unappealing task characteristics" and "insufficient task values". Over time, perceived "autonomy", "competence and relatedness support" negatively predicted change in "unappealing task characteristics" but did not significantly predict change in "deficiency in ability beliefs", "deficiency in effort beliefs" and "insufficient task values". Overall, the findings suggest that if students perceive their teacher to provide inadequate support for their basic psychological needs, PE tasks become less appealing over time, thus reinforcing the importance of teachers in ameliorating the development of specific amotivated behaviours in PE.