This study examined teachers' attitudes toward and implementation of the Competence-Based Curriculum (CBC) at Ntare School, a government-aided boys' boarding secondary school in Mbarara City, Southwestern Uganda. Using a mixed-methods cross-sectional design, the study collected data from 55 purposively and randomly selected teachers through a structured questionnaire, key informant interviews, and documentary analysis. Data were analysed using descriptive statistics, Pearson correlation, and multiple linear regression in SPSS Version 28.0, while qualitative data were analysed thematically. Findings revealed that teachers at Ntare School held moderately positive overall attitudes toward the CBC (M = 3.02, SD = 0.84), with the cognitive dimension recording the highest sub-score (M = 3.14) and the behavioural dimension the lowest (M = 2.93). A strong, statistically significant positive correlation was established between overall teacher attitude and CBC implementation (r = 0.73, p < 0.001). Multiple regression analysis indicated that teacher understanding of learner-centred pedagogy was the strongest predictor of implementation quality (β = 0.44, p < 0.001), with the model explaining 61.4% of the variance in implementation outcomes (R² = 0.614). Key implementation challenges included inadequate training, large class sizes, ambiguous assessment criteria, and a structural tension between examination performance pressure and CBC's competency-based philosophy. The study recommended sustained school-embedded professional development, clearer national assessment frameworks, improved ICT infrastructure, and institutional recalibration of success metrics as priorities for deepening CBC implementation at Ntare School and comparable institutions.