This study aimed to find out whether General Practitioners (GPs) use quality of life (QOL) information in primary care, to explore their reasoning and to assess any barriers to use. A second purpose was to see whether the Trans-Theoretical Model (TTM) of behaviour change could be applied to doctor's use of QOL information in primary care. A representative, cross-sectional sample of 800 GPs was approached in a national postal survey; 280 (38%) provided qualitative and quantitative information. Most GPs said that QOL was interesting and important. Users had seen more information and scales, and were more aware of its uses; only 8% had ever used formal standardised questionnaires. The main barriers to implementation were a shortage of time and information, and experience with using QOL assessment. A sizable minority wanted to know more. Seventy-one percent would use QOL to monitor treatment effectiveness. The five stages of the TTM were used to identify whether GP's were predisposed to use QOL information from their knowledge levels and values. While there was some support for the model, the TTM did not sensitively and reliably discriminate between users and non-users on all variables, and so has limited value here.