Poor participation in strategy formulation and absorption of development funds hinders effective strategy implementation, review and leadership in county governments and ultimately affects effective service delivery. The main purpose of this research study was to assess the influence of strategic management practices on Service Delivery in County Government of Nairobi City, Kenya. Specific objectives of the influence of the practice of strategic planning, strategic leadership and strategy implementation on service delivery formed the study. Descriptive and correlation research designs were adopted for the study. The study was anchored on Goal setting,systems, results and theory of everything in operations. The target population consisted of 130 respondents consisting of the county executive committee member, the chief officer, 2 directors, an accountant, finance officer, economist, supply chain officer and 2 office administrators from the thirteen (13) ministries in County Government of Nairobi as at January 2018. All the targeted 130 respondents in the 13 ministries in the County Government of Nairobi were sampled, thus forming a census study since the targeted population is specific in nature and limited in number. The questionnaire and interview schedules were used as the data collection instruments. Pilot study was conducted in the County Government of Kiambu using a sample size of 20 respondents to test the validity of the constructs of the questionnaire. Validity of the constructs of the questionnaire was further tested by a review of experts (the supervisors) while reliability was tested using reliability test. Data analysis and interpretation was based on descriptive statistics as well as inferential statistics mainly using SPSS. Analyzed data was presented using tables. Out of 130 questionnaires issued, 121 were filled and returned making it a return rate of 121(93.1%)