The study is aimed at studying the effect of personal characteristics (extraversion) on the effectiveness of construction Project Managers with a view to determining whether personality has any effect on the Project Managers’ performance. The study was carried out using two sets of questionnaires consisting of Eysenck Personality Questionnaire (EPQ) Adult Form and structured questionnaire to sample respondents’ personality and measure their effectiveness respectively. The study revealed that personal characteristics is a feature of every construction project manage in the study. However, extraverted construction project managers constitute 64% of the respondents while introverted construction project managers constitute 36%. It was revealed that the three areas where the respondents are more effective in order of ranking are effectiveness of meeting clients’ requirements in term of functionality of projects; effectiveness in terms of delivering the projects in terms of required quality standard; and effectiveness in terms of resolving conflict after occurrence before threatened project objectives which ranked first, second and third respectively. The study found out that there is a negative relationship between extraversion and effectiveness. The test of statistical significance using standard error and t-test showed no relationship between the variables. The t- value calculated (-0.297) is less than the t-tabulated (6.314) held at 0.05 significant level. Also, the alpha value (0.769) is greater than the –p value (0.0). It is recommended that another research should be carried out to find out if they have impact on Construction Project Manager’s effectiveness. Â