Successful implementation of a Competence Based Curriculum (CBC) in Kenya in primary schools greatly depends on the Teacher–Parent Partnership (TPP). CBC is a well-modelled form of education that provides opportunities for parents to take part in the education of their children. The teachers expect a well-modelled working relationship with each playing their role effectively for the realisation of good academic outcomes for learners with special needs. Empowerment of this partnership is inevitable, yet this is a resource that has remained underutilised. The teachers cited frustrations as the parents appeared not aware of their enormous role in the learning process both at home and school. The objective of the study was to establish the detriments of effective TPP in special primary school in Nyeri County, Kenya. The researcher adopted Epstein’s Model of parental involvement in the implementation of CBC. The study adopted a descriptive survey design method. A target sample of 47 teachers and 47 parents’ class representatives was used to obtain a sample of 14 class teachers and 14 parents (30%). Questionnaires for teachers and interview schedules for parents were used to collect data. The collected data were corrected, edited, and analysed using the Statistical Package for Social Science. The results were presented using frequency tables, charts, and graphs. The results revealed that parents were not aware of the roles in the implementation of CBC apart from paying fees and attending meetings when called upon. The teachers also reported that major detriments were affecting the partnership including gaps in the policies, lack of proper training on the skills, and pressure of completing the syllabus among others. The study thus recommends that there should be a policy that guides the partnership, a TPP manual for dealing with parents, and retooling of teachers on how to work with parents in the implementation of CBC.