Whether men and women behave differently in managerial roles is a much debated question. Many scholars developed different theories about the impacts of gender roles in understanding differences between male and female managers. Most studies also proved that gender role stereotyping resulted differences between male and female managers leadership style, value systems, effectiveness, career advancements, etc. Thus, this book deeply investigates the perceived differences between male and female managers on the job by using managers self and subordinates' evaluation. The study was targeted five randomly selected ministry offices found in Addis Ababa. The already developed Bem Sex Role Inventory (BSI) and Multifactor Leadership Questionnaire (MLQ) were used as data collection tools. An analysis of variance (ANOVA) on statistical measures was performed based on the number of responses obtained from male female managers self and subordinates evaluations. The most interesting findings revealed in this work are the presence of gender differences in leadership style, emergence, effectiveness, and acceptance.Finally, appropriate training and development programs are recommended.