This study examined neuroticism and extraversion as correlates of assertive behaviour among Nigerian Police Officers. A total of 107 participants comprising 65 male and 52 female Police Officers participated in this study. The 107 Police Officers were between the
age range of 24-33 years with a mean age of 28.5 and standard deviation of 2.11. The participants were drawn from the population of Nigeria Police Officers at the Nigeria Police Headquarters, Enugu, Enugu State, using available sampling technique. Two sets of instrument were used in generating data, the “Big Five Inventory (BFI) advanced by John, Donahue and Kentle (1991) and validated for use in Nigeria by Agbo (2013), and Rathus Assertiveness Schedule (RAS) developed by Rathus (1973), but validated for use in Nigeria by
Eze (2015). The researcher adopted Cross – Sectional Survey as this study’s design, while regression analysis” was applied in analyzing the data. The findings indicated a positive significant correlation between extraversion and assertive behaviour (â=.24, N=107, P<.01), while a negative correlation existed between neuroticism and assertive behaviour (â=-.24,
N=107, P<.01). The researcher recommends that parents and individuals should train, develop or socialize their children to become extraverted personalities so that they always stand up for their rights to voice out their feelings in any situation in a straight forward manner without causing any injury to others.