This study sought to assess the nuanced relationship between change management practices and the performance of health professionals within the devolved health function of Nyamira County, Kenya. Employing a descriptive case study methodology rooted in human capital and change management theories, the research aimed to comprehensively analyze the impact of leadership change, organizational culture, and communication channels on the performance of health workers. The study, conducted among 630 health practitioners seconded to the Nyamira County Government during the devolution of healthcare, utilized a purposive sampling technique to evenly represent 235 respondents across various cadres. Data was gathered through questionnaires, and the instrument's reliability was assessed using Cronbach's alpha. Quantitative data analysis involved SPSS and Microsoft Excel, with results presented through statistical approaches like tables, bar graphs, and pie charts. Contrary to initial expectations, the findings revealed a significant impact of leadership change on health worker performance, dispelling the notion that such changes had no effect in Nyamira County (β=. 0.442; p<.05). This rejection of the null hypothesis suggests a substantial influence of leadership transitions on health worker performance. In contrast, the study found no significant effect of organizational culture on health worker performance, as organizational culture did not emerge as a contributing factor (β=.0.199; p>.05). Communication channels also displayed a lack of significant influence on health worker performance (β= 0.334; p>.05), rejecting the null hypothesis and suggesting that the chosen communication channels had no remarkable impact. In conclusion, this study underscores the dynamic interplay between change management practices and health worker performance in Nyamira County's devolved health function. The unexpected findings contribute valuable insights, challenging assumptions about the influence of organizational culture and communication channels. These results have practical implications for the refinement of change management strategies, emphasizing the need for tailored approaches in the context of healthcare in Nyamira County.