This study examined changes in Pre-service teachers' (PSTs) Technological Pedagogical Content Knowledge (TPACK) and self-perceived stage of adoption (SOA) of technology as PSTs progressed through an online summer educational technology course. The longitudinal study was guided by the following research questions: 1) How did PSTs' externally assessed TPACK and self-perceived SOA change over the duration of the online summer educational technology course? 2) Is there a relationship between TPACK and SOA, in particular, are weekly SOA self-reports predictive of TPACK? Linear mixed growth model analysis indicated significant growth in group TPACK that could be attributed to the course design and PSTs' course experiences with technology. For SOA the same model indicated significant linear growth but the residual variability in SOA scores was about five times larger than the residual variability in TPACK scores. Moreover, SOA was not an important predictor of TPACK over the duration of the study period.