Objectives: The aim of the study was to examine the relationship between work engagement, burnout and coworker support, social climate at work, work-language proficiency and post-migration job skill change, among international migrant workers. Material and Methods: Polish versions of Utrecht Work Engagement Scale, Burnout Assessment Tool, and the second Copenhagen Psychosocial Questionnaire were used for the measurement of the studied variables. All participants were recruited using announcements at Polish diaspora online forums and snowball sampling. The questionnaire was submitted to them in a form of an anonymous online survey. Results: From 420 questionnaires filled in by the respondents, 411 were qualified for analysis. The results of a multiple regression analysis indicate that a positive perception of the social climate at work increases the scores of general work engagement (β = –0.22, p = 0.001), as well as all its subscales: dedication (β = –0.14, p = 0.002), vigor (β = –0.20, p = 0.001) and absorption (β = –0.22, p = 0.001). Support received from coworkers has a positive influence on the vigor dimension (β = –0.14, p = 0.002). Furthermore, work-language proficiency can be associated with more engagement F(1, 409) = 37.66, p = 0.000 and less burnout F(1, 409) = 11.68, p = 0.000 than limited work-language knowledge. In a similar manner, increased or similar job skill level compared to one’s last employment in the sending country may be associated with better engagement F(2, 408) = 33.88, p = 0.000 and fewer symptoms of burnout F(1, 409) = 7.96, p = 0.005 than post-migration decrease of job skill. Conclusions: The perception of social climate at work and coworker support have shown to be positive predictors for particular dimensions of work engagement. Moreover, work language proficiency and job skill have been shown to associate with work engagement and burnout.