In Kenya’s last four presidential elections, election observers had been seriously looked upon by both the Kenyan voters and the international community to provide alternative but credible information on the process and outcomes of presidential elections in Kenya. This was expected to promote legitimacy of the outcomes. Given that there was a dearth of specific scholarship to address the question, this study was conducted. This paper therefore examines the effectiveness of multitrack diplomacy in monitoring Kenya’s presidential election outcomes. The study was epistemological. It was conducted in 8 of the 17 constituencies of Nairobi City County which hosts the Kenya’s largest city and its capital with a natural representation of the population of the entire country. Out of the over 4 million residents of Nairobi City County, total sample size was 441 (384 questionnaire respondents, 32 focus group discussion participants and 25 key informant interview respondents). The study reached 436 (384 questionnaire respondents, 32 focus group discussion participants and 20 key informant interview respondents) out of 4 million people. Targeted were Kenya citizens who had voted at least once for a presidential candidate in any of the presidential elections held between 2007 and 2017 for the survey; individuals working with and for government institutions in Kenya’s electoral systems especially the election management body, ministry of foreign affairs, members of parliament, the Chief Justice, pollsters, the media, non-governmental organizations, religious institutions across all faiths as to Muslims, Christians and Hindu, major political parties, former election observers and diplomatic missions. The study found that multitrack diplomacy (MTD) actors or election observer missions (EOMs) observed election irregularities to above 50%. They detected electoral fraud in the 2007 presidential elections, identified election irregularities in the 2013 and the 2017 presidential elections but could not deter nor prevent outcome fraud. The paper, based on the study, concluded that multitrack diplomacy actors that monitored the presidential elections were fairly effective, they had reasonable capacity, fairly above 50%. Overall, multitrack diplomacy is effective in monitoring of Kenya’s presidential election but inefficacious in preventing and deterring election outcome fraud. Multitrack diplomacy actors-the election observation missions (EOMs) to use enhanced technology to match the electoral systems technology, improve on their objectivity during monitoring and be granted full accesses by governments and election management bodies (EMBs) for systematic, comprehensive and accurate monitoring.