The main objective of this study is to investigate the mediating effects of organizational citizenship behavior (OCB), destructive deviant behaviors (DDB), constructive deviant behaviors (CDB), and workaholism (WA) in the relationship between work ethic (WE) and the productivity of engineering students. Another objective is to present a comprehensive holistic model of relationships of these organizational behaviors (OB), attitudes, and work ethic with the productivity. Structure equation modeling (SEM) and Hayes’ processes are used to analyze the hypothesized model. Data were randomly collected from 400 participants from the universities of Pakistan. The overall assessment of the model showed that WE indirectly effects productivity through mediating variables (OCB, DDB, CDB, WA). One of the implications of this finding is that education practitioners/planners should promote work ethic (considered essential for sustainable management practices by contemporary researchers also) among engineering students. This ethic will be reflected in students’ behaviors (enhanced positive behaviors/attitudes, i.e., OCB, CDB, and WA, and reduced negative behaviors i.e., DDB) which will in turn improve their productivity. The originality of this research lies in it being the first to explore the indirect effect of Islamic work ethic (IWE) on individuals’ productivity through OCB, DDB, CDB, and WA.