The book highlights the Working of Trade Unions -A Study in Tamil Nadu State Transport Corporation Limited. Trade Union is an association of workers formed mainly for the purpose of protecting and promoting economic and social interests of its members through action. The present study deals with various dimensions of trade unionism in Tamil Nadu State Transport Corporation in Trichirappalli Region. The main objective of the study are to study the profile of trade unions in Tamil Nadu State Transport Corporation, inter-union and intra-union relations, fulfillment of members expectations and role of trade unions in industrial relations. The results revealed that internal employee leader functions more effectively than the external leaders. The member's participation in trade union activities was found to be above the average. The trade union activities in Tamil Nadu State Transport Corporation had increased from year to year in Trichirappalli.