Dissertation (Master in International Relations)The study focused on voters’ perception on participation of international election observers in Tanzania’s 2015 presidential election, a case of Ilala constituency in Dar es salaam region. The general objective of this study was to assess voters’ perception on participation of international election observers in Tanzania’s 2015 Presidential elections. Descriptive cross-sectional survey technique was used and systematic random sampling was employed to select respondent for the study. The sample size for the study was 100 respondents and research instruments used were survey questionnaires, structured interviews and documentary review. Findings revealed that while voters have good understanding about the concept of international observers, on the other hand a majority of them had little knowledge on the declaration principle of observation missions. Study results show that, majority of respondents have negative perceptions about the participation of international election observers in elections. On the other hand, findings show that a majority of respondents rated the roles of international election observers as either less effective or not effective at all. Furthermore, in assessing voters’ view on the effects of international election observers in elections results show that, majority of respondents were either strongly disagreed or disagreed that, international election observers had effects in elections. On top of that, the result show that, the majority of respondents see the need to invest in more information election observation project. The study therefore, recommends that more education about international observers should be provided to the community so as to increase awareness and importance of International election observer’s participation in election.