Self-regulatory efficacy (SRE) among elementary school children is of interest because pupils' self-regulation capacities and SRE influence in managing learning situations. This study investigated variations in the four sources of SRE and how these variations were related to SRE, reading skills and arithmetic skills. The participants were 1284 pupils in Grades 2 to 5. SRE and the sources of SRE were explored via questionnaires completed by the pupils. Latent profile analysis was used to search for subgroups with similar combinations of sources. Five distinguishable and informative profile groups emerged with differences in SRE levels and basic academic skills. The greatest variations were in mastery experiences and emotional states, which were the most sensitive sources for detecting interindividual differences in the domain of self-regulation. Multiple positive sources contributed to higher SRE, while low exposure to sources was related to both lower SRE and low basic academic skills.