Gardner’s socio-educational model of second language acquisition has received substantial attention from L2 researchers. Several scholars, however, came to question the applicability of the model into foreign language learning (FLL) situations because Gardner’s model was based on studies that have utilized samples selected from Canada, which is presumed to be a typical context of second language learning (SLL). Therefore, the present study investigated the generalizability of Gardner’s socio-educational model into FLL situations by using two samples of Korean learners of English selected from the USA (i.e., ESL sample) and Korea (i.e., EFL sample). To this end, a multi-sample Structural Equation Modeling (SEM) analysis was performed to examine the factorial similarity of Gardner’s model across the ESL and EFL sample. Results of the SEM analysis indicated that the socio-educational model may also hold for learners of L2 in FLL situations. Further multi-sample analysis identified parameters that were not invariant across two samples of Korean learners of English, hence highlighting a call to fine-tune the Attitudes/Motivation Test Battery (AMTB) for use in the context of FLL.