This study elucidated how humanistic teaching as manifested in teachers’ error correction influences EFL learners’ engagement, motivation, and language achievement. the present study was carried out in a language Institute in Mashhad, Iran. The population comprised 42 advanced female learners. To investigate how error treatment will affect EFL learners’ engagement, intrinsic motiv ation and language achievement, a mixed -methods design incorporating both quantitative (experimental design) and qualitative (interview & observation) methods (QUANqual) was employed. The participants were divided into control and experimental groups. Speaking errors of the participants of the experimental group were corrected by three methods of corrective feedback including peer-correction, elicitation, and repetition, whereas, speaking errors of the participants of control group were directly corrected by the teacher. To measure the intrinsic motivation, the MSLQ questionnaire (Pintrich, et al., 1991) was employed. Students’ engagement was determined through Tool-school engagement scale, which was assesses behavioral, emotional, and cognitive aspects of academic engagement (Fredericks, Blumenfeld, Friedel, & Paris, 2005). A Babel test was utilized to assess language proficiency. To examine the effect of corrective feedback on intrinsic interest, an independent samples t-test was run. The results substantiated the efficiency of corrective feedback in enhancing intrinsic motivation. A one-way between-groups multivariate analysis of variance (MANOVA) was utilized to investigate the role of corrective feedback in Cognitive, Behavioral, and Emotional Engagement. It was revealed that all three types of engagement were influenced and the highest difference was observed in Emotional engagement and the lowest difference was obtained for Behavioral engagement. Regarding language achievement, the results implied that corrective feedback utilized in the experimental group resulted in higher language achievement. Twenty-five percent of the whole participants were interviewed after the term. The findings analyzed via MAXQDA software were in line with the results of the quantitative phase.