In Kenya, the public procurement sector has developed over the past 5 decades, from a system with no regulations to a system regulated by circulars; and currently, to a system firmly grounded on sound laws and policies. The aim of this study was to establish the extent to which public secondary schools in Nairobi City County had complied with relevant legislative and policy provisions guiding procurement reforms, as well as the effect of selected  of reforms on expenditure management. This article focuses on the frequency of tender advertising. The evaluation research model III was applied to guide the research process and primary data were sourced in 2015 from 35 public secondary schools. Quantitative analysis included cross-tabulation with analysis of variance, chi-square statistic, correlation coefficient, as well as multiple regression. The study found that two-thirds of the schools were consistently advertising tenders as required by the legislative and policy provisions. Besides, the frequency of tender advertising significantly correlated with variation in procurement expenditure; and further caused a significant reduction in the same (beta weight = -0.335, t-statistic = -2.639 & ρ-value = 0.014), which signifies a positive influence on expenditure management. Ensuring consistency in advertising tenders is likely to help many schools improve on expenditure management; thereby, enhance the contribution of public procurement to national development.