Purpose/ Aim: The purpose of this paper is to investigate whether females have different perceptions of diversity management and workplace happiness compared to their male colleagues. Furthermore, the paper explores whether diversity management perceptions mediates the relationship between workplace happiness and organisational citizenship behaviour. Design/Methodology/Approach: A total of 260 questionnaire from a number of public hospitals in Egypt were analysed using both t-test and Structural Equation Modelling. Findings/ Results: We found that female physicians perceive diversity management policies/protocols more positively than their male colleagues. Moreover, gender has no or little effect on physicians’ perceptions of workplace happiness. We also found that workplace happiness positively affects physicians’ organisational citizenship behaviour, and finally, diversity management practices can mediate the relationship between workplace happiness and physicians’ organisational citizenship behaviour. Social and practical implications: We believe that managers can raise the feeling of workplace happiness among their staff if they maintain some personal relationships with physicians, care about the physicians’ work/life balance, promote after work gatherings, initiate coffee time talks, encourage open communication practices and more. Originality: The paper is based on the argument that although employees might be happy in the workplace through (engagement, job satisfaction, affective commitment), however their happiness will be unlikely reflected into a positive organizational citizenship behaviour towards their organisation, except (social exchange theory) they feel or perceive (equity theory) the overall practices of diversity management in that organization positively. Thus, studying the mediating effect of perceptions towards diversity management is mainly our contribution.