Purpose: This study aims to explore the underlying mechanisms of the less studied relationship between perceived corporate social responsibility (CSR) (both internal and external) and creative deviance (CD). Based on the signalling and social capital (SC) theories, this study proposes that the relationship between CSR and CD is mediated by both the prosocial motivation and SC of the employees. Design/methodology/approach: This study conducted a survey approach to gathering data and implemented a structural equation modelling technique for analysis. Findings: Data collected from telecom employees supported the sequential mediation of both SC and prosocial motivation on the relationship between internally and externally perceived corporate social responsibility and CD. Research limitations/implications: The in-depth analysis of the similarities and differences in the internal and external dimensions of CSR is valuable for understanding the antecedents of CD. Practical implications: The in-depth analysis of the similarities and differences in the internal and external dimensions of CSR is valuable for understanding the antecedents of CD. Managers can use this knowledge to improve their performance by following better CSR practices that in turn foster SC and CD. By supporting SC, companies will be able to increase their intellectual capital (IC), which is necessary to compete in today's markets. Originality/value: The present literature is mostly silent on the differences and similarities between perceived CSR and employee creative behaviour: CD. The present study fills this gap by investigating this important relationship and testing its underlying mechanisms for internally and externally perceived CSR separately. The paper puts forward the key role of SC, which is part of IC, in reinforcing the relationship between CSR and CD.