The implementation of Public Procurement Act is faced by several challenges. This study was done to identify the level of influence of the challenges the public secondary schools face in the implementation of PPDA in Nairobi County. The objectives were to determine the extent to which familiarity with regulations, communication, executors and commitment influence the implementation of PPDA. The main research questions determine to what extent familiarity with regulations, communication, commitment and the executors influence implementation of PPDA. The study research design is correlation as it sought to analyze the degree of relationship between the variables. The study adopted a mixed-mode approach method whereby quantitative and qualitative techniques are used. The target population was the tender and procurement committee members in the selected public secondary schools from eight constituencies in Nairobi County. Data was analyzed using computer software's (Excel and Statistical Package for Social Scientists (SPSS)) because of their user friendliness and ability to analyse multi-response. Study findings indicated that it can be noted that familiarity of procedures is a significant predictor of compliance with PPDA regulations with a strong correlation obtained of 0.721. The executors had a moderately strong relationship in the implementation of PPDA with a correlation value of 0.672 while communication variable showed a moderately strong correlation with the implementation of PPDA. The commitment variable showed a weak correlation value of 0.173 with the implementation of PPDA. There was the one third rule in the gender representation in the sampled population with 39.7% being women. Most of committee members were aged between 40-50 years, being 74.5% of the population. The researcher recommended the PPOA and the public entities to work together to improve on the familiarity of committee members with public procurement procedures through taking procurement skills assessment and training staff through refresher courses, workshops, seminars and conferences where staff meet and share experiences. PPOA to also push the government to employ a professionally trained procurement officer in each school who will assist the committee in procuring as required by the PPDA to increase compliance. Frequent evaluations and reviews for the schools to be done to ensure compliance where all schools will be informed of their non-conformities and informed of what should be done as per the regulations of PPDA. The researcher recommended the government to also adopt e-procurement in all public entities to enhance communication between all the stakeholders as well as transparency in the procurement procedures in the implementation of the PPDA. A further study recommended by the researcher is to be carried out (longitudinal study) to examine true compliance with public procurement regulations in the public schools over time. An investigation of the environmental factors causing non-compliance in public schools as well as factoring of professionalism in the implementation of PPDA in public schools would also be useful in explaining noncompliance.