An analytical framework of the referral decision was applied to the question of whether general practitioners (GPs) with relatively high and relatively low referral rates differed in the types of factors that influenced their referral decisions. Interview data from six high referring and six low referring GPs were compared at all levels of the framework, using both quantitative and qualitative content analysis. High referrers were found to mention significantly more negative factors than low referrers, i.e. they referred 'in spite of’ reasons against referral. In particular, they referred patients in spite of having doubts about treatment effectiveness. Low referrers mentioned factors related to interpersonal processes significantly more often than high referrers, for example, GP-patient communication as an influence. Possible interpretations of these findings are discussed.