Abstract:Psychological distress has become a serious issue with consequent negative outcomes on individuals and organisations. This study investigated the mediating roles of resilience and optimism between work demand and psychological distress among preschool pupils' caregivers in Ekiti State, Nigeria. A descriptive survey research design was adopted. A sample of 605 caregivers was chosen through stratified random sampling technique. Data were collected using: (i) Demographic Data Form, (ii) Kessler Psychological Distress Scale, (iii) Perceived Work Demand Scale, (iv) Connor-Davison Resilience Scale, and (v) Life Orientation Test Revised. Data were analyzed using Regression Analysis and Pearson Product Moment Correlation Coefficient with result tested for significant at .05 level. Findings revealed, among other things, that there is a significant positive relationship between psychological distress and resilience (r = .263; p <.001), but not between psychological distress and optimism (r = .010; p >.05) and psychological distress and work demand (r = .071; p >.05). There was no significant direct effect of work demand on psychological distress of caregivers, independent of resilience and optimism (coeff = -.043; p >.05). Resilience mediated between work demand and psychological distress of preschool pupils' caregivers. However, neither optimism nor both resilience and optimism did not. The study concluded that resilience and optimism are not significant mediators between work demand and psychological distress of preschool pupils' caregivers. Based on the findings, it was recommended, among others that other factors that could cause a positive relationship between psychological distress and resilience should be identified, isolated, and controlled for further research.