The purpose of the study was to investigate the factors influencing performance of events management service providers in Nairobi County, Kenya with a view to highlight the most salient determinants of event management success. Event Management Body of Knowledge (EMBOK) constituted the theoretical framework for this research. The study adopted a descriptive research design. The population of the study was 196 event management companies in Nairobi. A modest sample of 39 of the companies was selected using stratified random technique. Data was collected using a structured questionnaire. Descriptive statistical techniques such as percentage frequencies, mean and standard deviations was used to analyze data. The data was presented in the form of frequency tables, charts and graphs for ease of analysis and interpretation. The study established that in terms of performance rating, customer satisfaction was the highest (M=4.77, SD=0.430), followed by time efficiency (M=4.70, SD=0.466), and budget efficiency (M=3.37, SD=0.490) while profitability was the least rated on a 5-point scale (M=2.97, SD=0.718). The results showed that on aggregate, event risk factors potentially had the greatest influence on wedding event management performance (M=4.43, SD=0.549), followed by event administration factors (M=4.30, SD=0,604) and lastly, event operation factors (M=4.19, SD=0.576). The study concluded that Event risk factors was the most salient determinant of event management success. This was reflected in the emphasis put on astuteness in decision making as a basic requirement for surviving and thriving in the wedding event management business as well as risk prevention measures through detailed security, health and safety measures as well as legal compliance to mitigate risks. Event operation followed as the second EMBOK domain that potentially influenced performance of wedding event management service providers. A number of event operation factors were especially salient such as the experience of the staff team. Time management was also a critical success factor in tow, as was budgetary issues, whereby difficulty in accurately estimating the budget due to price fluctuations was a key challenge confronting player in the wedding industry. Event operation factors also did potentially influence performance of wedding event management companies although not as much as event risk or administration domains. The study recommends that event management companies should develop risk-adjusted budgets that should inform quotation decisions. Wedding budgets need to be informed by a thorough research and forecasting of future prices and changes that may take place as the event date neared. In order to reduce exposure to price fluctuations and enhance budget efficiency, event management companies should sign hedge contracts with the main vendors and suppliers in a wedding. Further, the experience of the staff needs to form the basis of hiring decisions in an event management firm. These findings could be useful to events management service providers as they seek to deliver quality services to their clients.