this work analyses the role of satisfaction in the formation of customer loyalty. it identifies the most relevant antecedents of satisfaction, and determines their influence on loyalty through judgments of satisfaction, performance, and disconfirmation. it distinguishes between an attitude of loyalty, positive and negative intentions, and behavioural loyalty or effective purchasing. it studies a sample of purchases in retail clothing and food establishments, using the methodology of the mediator effect. the result of the regressions show that satisfaction is a mediating element between the effects of performance and disconfirmation on positive intentions, and between the effect of performance on behavioural loyalty. no relationship was found between satisfaction and negative intentions.