Background The aim of this study was to describe the range of screenin
g services offered by general practitioners (GPs). Methods A postal qu
estionnaire survey was sent to a random sample of one in four GPs in g
eneral practices within the geographical boundaries of North (East) Th
ames Region. The questionnaire was divided into five sections, the fir
st covering practice details and the other four covering screening dir
ected at different groups of patients. Each GP in the sample was sent
the general section and two other sections. Results The overall respon
se rate was 67.7 per cent. There was inter-practitioner variability in
screening practice in all four patient groups. A number of GPs did no
t undertake all screening tests required by the national GP contract o
r recommended by national or local policy, and some had introduced scr
eening programmes of uncertain benefit. There was little evidence of s
ystematic audit of screening programmes. Differences in screening obse
rved between GPs in Greater London metropolitan areas, but there was l
ittle difference between single-handed and group practices, or between
fundholding and non-fundholding GPs, except in the provision of child
health surveillance. Conclusion Primary care teams carry out screenin
g for a wide range of conditions but the lack of uniformity of practic
e and of evaluation makes it unclear to what extent the population ben
efits from these activities. The importance of national and internatio
nal screening policies is obvious, but there is a need to go beyond pu
blication and dissemination of guidelines to develop implementation st
rategies which take account of the variations in the way GPs actually
address screening in their practices.