Community health centres in Nigeria have been established to improve healthcare access and outcomes for underserved populations. However, their effectiveness has not been systematically assessed. We employed the DiD model to compare changes in healthcare utilization and service quality between intervention and control communities. Data were collected from secondary sources including government reports and surveys conducted by non-governmental organizations. The analysis revealed a statistically significant increase (p < 0.05) in patient consultations per visit duration, suggesting improvements in service efficiency. DiD modelling provided robust evidence of yield improvement in community health centres, indicating their effectiveness in enhancing healthcare access and quality. Further research should explore the sustainability and scalability of these findings across different regions to inform policy decisions. community health centres, difference-in-differences model, Nigeria, yield improvement Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.