A Dissertation Submitted in Partial Fulfillment of the Requirement for the Degree of Masters of Science in Procurement and Supply Chain Management (MSc-PSCM) of Mzumbe University.This research assessed factors influencing the effective implementation of annual procurement plan at Tanzania Communications Regulatory Authority and Tanzania Building Agency. The general aim of this study was to assess the factors influencing effective implementation of Annual Procurement Plan. The specific objectives of the study were to assess the influence of preparation of annual procurement plan, staff competency, financial resources and internal control systems on implementation of Annual Procurement Plan. The study was carried out in two Agencies namely Tanzania Communication Regulatory Authority and Tanzania Building Agency at Dar es Salaam region. The study used a case study research design by comparing the two Agencies. The Target Population of the study was 72 from Tanzania Building Agency and 67 from Tanzania Communications Regulatory Authority that also provide the sample size of 72 and 67 respectively. Data was analyzed through descriptive statistic, correlation and regression analysis. In relation to first objective, the findings indicated that there was positive relationship between preparation of annual procurement plan and implementation of Annual Procurement Plan at a significance level of 0.019. The second objective showed that there was positive relationship between staff competency and implementation of Annual Procurement Plan at significance level of 0.000. For the third objective the results revealed that financial resources have significant contribution to the implementation of Annual Procurement Plan at significance level of 0.014. The fourth objective indicated that internal control system has positive significant relationship with implementation of Annual Procurement Plan at a significant value of 0.001(P<0.05). The study concludes that from regression model; the research concluded that there is a positive relationship between resources allocation, preparation of annual procurement plan, staff competency and project delivery. The study concluded that procurement expertise and knowledge’s have great impact on the preparations of procurement plans within both Agencies. Therefore, the study recommended that there is a need for both agencies to continue providing training to the staff within Procurement Management Unit so as to equip them with technical skills on procurement and its regulations.