To examine the organisational (i.e., perceived organisational support and psychologically safe environment) and individual (i.e., value, belief and norm) antecedents that strengthen healthcare workers' speaking-up behaviour in a developing economy. The study uses a cross-sectional design to gather the same data from healthcare workers within the Ashanti Region of Ghana. The data collection happened between 15 June and 30 August 2023. A sample of 380 healthcare workers was selected from 20 facilities in the Ashanti Region of Ghana. A configurational approach, a fussy-set qualitative comparative analysis, was used to identify the configurations that caused high and low speaking-up behaviour among the study sample. The study results reveal that whereas four configurations generate high speaking-up behaviour, three configurations, by contrast, produce low speaking-up behaviour among healthcare workers. Results suggest that in so far as organisational support systems which take the form of a psychologically safe environment and perceived organisational support are vital in relaxing the hierarchical boundaries in a healthcare setting to improve healthcare workers' speaking-up behaviour, the individual value-based factors that take the form of values, beliefs and norms are indispensable as it provides the healthcare workers with the necessary inner drive to regard speaking-up behaviour on patient safety and care as a moral duty. Healthcare workers' speaking-up behaviour is better achieved when organisational support systems complement the individual norms, values and beliefs of the individual. Adhered to Strengthening Reporting of Observational Studies in Epidemiology guidelines. No patient or public contribution.