This thesis examined the antecedents and consequence of trade union commitment in Nigerian trade unions. Data obtained from 512 unionised employees in Nigeria was analysed using mainly correlation and regression analysis. From the results, the significant predictors of union commitment were factors associated with union characteristics and perception namely union instrumentality perception, satisfaction with union leadership and early union socialisation experience. Sector was a significant moderator in the model: union commitment was greater in the public sector while union participation was greater in the private sector. Males participated significantly more in union activities than females although there was no significant gender difference in union commitment. Factors associated with union attitudes were found to moderate the relationship between union commitment and union participation. Union commitment was also found to predict union participation in the overall model as hypothesised. The qualitative study involved personal interviews as well as content analysis of relevant union materials including logbooks. The results confirmed the relevance of the unions' settings and specific individual experiences to the quantitative findings. The overall findings provided limited support for the view that antecedents of union commitment differ across countries or contexts. Because some of the findings were partially consistent with those from the western literature, it cautions against generalising a notion that western models are dysfunctional in developing countries. The applications, implications and limitations of the findings were discussed.