This paper uses data from a survey of Canadian establishments to consider the effects of computer-based process technological change on wage bargaining power. The analysis finds that union wage differentials for blue-collar workers as a whole were lower among firms that had introduced process computerization than among those that had not. The relationship between technological change and the union wage premium differed, however, for skilled and unskilled labour. The union wage effect was lower for skilled workers and higher for general manual occupations in the sub-sample where process computerization had occurred. Explanations for these observed relationships appear to involve both economic and institutional components.