This study examined the relationship between the availability of instructional resources and the effective implementation of the competence-based curriculum (CBC) in public primary schools in Wakiso District, Uganda. Competence-based, learner-centred instruction depends heavily on the availability of adequate and varied instructional resources, yet resource provision in public primary schools remains uneven. The study investigated how print materials and textbooks, audio-visual and digital resources, teaching aids and realia, and library and reference resources relate to effective CBC implementation. A cross-sectional survey design with a mixed-methods approach was adopted, and data were collected from 200 respondents comprising teachers, head teachers, and education officials using structured questionnaires, a resource inventory checklist, and interviews. Descriptive statistics, Pearson correlation, and regression-based path analysis were used. The results revealed a strong positive and significant relationship between the availability of instructional resources and effective CBC implementation (r = 0.65, p < 0.01), with the resource categories jointly explaining 62.0% of the variance in implementation (R² = 0.620). Audio-visual and digital resources and print materials and textbooks emerged as the strongest predictors. The study concludes that adequate instructional resources significantly enhance CBC implementation and recommends increased and equitable provision of resources, particularly audio-visual and digital materials.