The study examined the relationship between activities of trade unions and management of tertiary institutions in a bid to provide empirical solution to the lingering industrial actions by the staff unions in various tertiary institutions in Nigeria. 450 subjects consisted of 390 members of unions which were selected using proportionate sampling techniques and 60 top management staff of the selected institutions was selected purposively. Two self-designed instruments namely; “Trade Unions and management of Tertiary Institutions Questionnaire (TUMTIQ) and “Management of Tertiary Institutions Questionnaire (MTIQ)” were used to collect relevant data from the subjects. The face and content validity was done by the researchers and another expert in Educational management and Test and Measurement. Also test-retest method of reliability was adopted with reliability coefficient of 0.66 and 0.72 respectively. The data collected were analysed using descriptive and inferential Statistics and the three hypotheses were tested at 0.05 level of significance. The study revealed that there was significant relationship between activities of trade unions and leadership style of management of tertiary institutions. The study also showed that there was significant relationship between trade unions’ dissatisfaction with conditions of service and management of tertiary institutions. Based on the findings of the study, it was recommended that management of tertiary institutions should adopt a leadership styles that is all inclusive through participatory system of management. Government should also provide funding for management to enhance condition of service in form of better pay package, in-service training, overseas trip and their welfare packages for staff