Project-based learning activities commonly occur as part of science classroom instruction. However, while there is a large body of research about self-regulation of discreet tasks, there is limited research about how students sustain self-regulated learning during complex, long-term learning tasks. A multiple case study design with quantitative and qualitative data sources was used to investigate how middle school students with learning disabilities (LD) self-regulated their learning during a complex, science-based project--creation of computerized serious educational games (SEG) about renewable energy sources. Findings revealed three replications of the expected relationships between student-reported strategic effort attributions and self-efficacy. Specifically, strategic effort attributions related to positive self-efficacy, and non-effort attributions (or no attributions) related to inconsistent self-efficacy. Theoretical implications are presented.