To determine how succession-planning practices influences employee performance in South Sudan’s Ministry of Public Service, a setting that is simultaneously grappling with imminent retirement waves and the need to safeguard institutional knowledge. A mixed descriptive-correlational design combined quantitative surveys with qualitative follow-ups. Stratified random sampling produced 303 targeted respondents (75 recent retirees; 228 current employees); 286 usable questionnaires yielded a 94.4 % response rate. A five-section Likert instrument (Cronbach’s α = 0.843 – 0.892) captured succession-planning practices and performance indicators. Descriptive statistics profiled both constructs, Pearson correlation assessed their association, and simple linear regression tested predictive power. Qualitative comments from open-ended items were thematically analysed to enrich interpretation. Succession planning was judged moderately effective (overall mean = 3.80, SD = 1.10), excelling in successor identification (mean = 3.92) and training (3.89) but weaker on employee involvement (3.69) and communication (3.75). Employee performance was rated high (mean = 4.06, SD = 0.96), with strongest scores on continuous improvement (4.11) and meeting expectations (4.10). Correlation analysis indicated a strong positive link (r = 0.574, p < 0.001). Regression results showed that succession-planning progress explains 32.9 % of performance variance. Thus, a one-unit rise in succession-planning effectiveness predicts a 0.659-unit increase in employee performance. Qualitative feedback echoed these findings, citing clearer career pathways, mentoring from retirees, and transparent replacement charts as performance catalysts. The study extends Human Capital and Social Learning theories by quantifying how structured, participatory succession systems translate into measurable performance gains in an emergent public-sector context. Policymakers can use the results to embed mandatory succession framewo