This paper uses longitudinal data for a sample of Italian firms to study the effects of technological and organisational changes on wage levels and on wage differentials by skills inside the firm. Fixed effect estimates reveal that technological changes are associated with higher absolute and relative wages for skilled workers. About organisational changes, initially their relationship with firms' wages is negative, but it becomes positive in subsequent periods, especially for skilled workers. Finally, there is no evidence that the wage increase is higher when technological and organisational changes are adopted in conjunction instead of separately.