In the dynamically changing environment, knowledge is becoming the most important resource for organisational performance, surpassing other resources such as land and capital. Therefore, retaining organizational knowledge is the key characteristic of sustainable improvement in organisational performance. On the contrary, publicly funded research institutions in Kenya lose experts' knowledge from retiring employees. Knowledge management in publicly funded research institutions in Kenya seems to be a major challenge contributing to poor service delivery and gaps in work performance. Therefore, based on the Human Capital theory, this study sought to fill the gap by establishing the influence of knowledge retention practices on the performance of publicly funded research institutions in Kenya. The study used stratified random approaches to sample 135 respondents out of 6,799 employees in Kenya's 12 publicly funded research institutions. Both qualitative and quantitative primary and secondary data were collected to achieve the study objectives. While qualitative data was analysed through thematic methods, quantitative data were analysed using both descriptive statistics (mean scores, percentages and standard deviation) and inferential statistics (Multiple Regression Analysis) through the Statistical Package for Social Sciences (SPSS) version 24. It was established that adopting knowledge retention practices such as succession planning, use of retirees, mentoring and coaching are associated with a significant positive influence on the performance of publicly funded research institutions in Kenya. Based on the findings, the study recommends the management of public research firms provide regular training and mentoring programs to employees to help them retain knowledge and improve their skills. The organizations can also conduct exit interviews with departing employees as a useful way to capture their knowledge and insights before they leave the organization. This information can then be used to improve knowledge retention and prevent the loss of critical knowledge.