We investigated the effectiveness of the 360-credit National Professional Diploma (NPDE) as a programme that is aimed at the upgrading of currently serving unqualified and under-qualified educators, with a view to improving the quality of teaching and learning in schools and Further Education and Training colleges. To this end, the National Professional Diploma in Education Effectiveness Scale (NPDEES) and Classroom Observation and Assessment Form (COAF) were used. The findings indicated that educators differed in the extent to which they regarded the 360-credit NPDE programme as effective. The findings also indicated that component 3 (competences relating to teaching and learning processes), component 1 (competences relating to fundamental learning) and component 4 (competences relating to the profession, the school and the community) were the best predictors of the effectiveness of the 360-credit NPDE programme. It was found that educators differed in the extent to which they performed during the classroom-based evaluation. Suggestions are made for measures to improve educators' performance in the classroom.