The aim of the article is to address the determinants of job satisfaction for knowledge-based workers in Spain. The empirical analysis is focused on wage earners aged between 16 and 65 years. To do this, microdata of 6499 workers from the 2010 Survey of Quality of Life at Work (Encuesta de Calidad de Vida en el Trabajo, ECVT in Spanish) was used. An ordered probit model, which is designed to model the choice between discrete alternatives, was preferred for the econometric analysis. Our results highlight the fact that knowledge-based workers perceived significantly higher job satisfaction than less-knowledge-based workers. Evidence suggests that financial (only satisfaction with social benefits provided by firm) and non-financial (work organisation, labour relations and skills and training) job dimensions are the most important determinants of knowledge-based workers satisfaction in Spain. Additionally, stress, monotony, physical effort, labour discrimination, risk levels and commuting time have negative effects.