This study investigated first and second grade students’ peer-relatedness, quality of L2 motivation, and their agentic and behavioral engagement in Turkish EFL classrooms. Students’ sense of relatedness was measured through the Relatedness to Social Partner Questionnaire (Furrer & Skinner, 2003), which was presented orally to students. Students’ quality of motivation was assessed with a Thematic Apperception Test-Like (TAT-Like) projective measure (Katz, Assor, & Kanat-Maymon, 2008) in one on one interviews with students. Their agentic and behavioral engagement were measured through a short survey adapted from the Behavioral Engagement Questionnaire (Skinner, Wellborn, & Connell, 1990), which was filled by EFL teachers. Therefore, a mixed method and corss-informant assessment was adopted. The sample included 62 first and second grade students along with eight EFL teachers from five private schools in Ankara, Turkey. Students participated from 10 different EFL classrooms. Logistic regression analysis showed that these students’ sense of peer relatedness was positively and significantly related to their autonomous motivation in EFL lessons. There was not any significant relation among students’ sense of peer relatedness and their agentic and behavioral engagement. Similarly, no significant relation was found among students’ quality of L2 motivation and their agentic and behavioral engagement. Supplementary analyses (non-parametric 2-independent Mann Whitney U Tests) showed that students with only autonomous motivation do not differ from students with only controlled motivation in their agentic and behavioral engagement. The findings of the study underscore the importance of the social environment in the elementary EFL classroom for young students’ quality of motivation.