When patients bypass one health facility to seek care at another, strong preferences are revealed. The patterns of bypassing observed in Iringa Rural district in Tanzania show evidence of patients' understanding of various measures of quality at the facilities that they visit and bypass. We match two data sets that measured quality in health facilities with a sample of patient choice of health facilities. We use a conditional logit regression on patient choice of provider to show the relationship between patient behaviour and objective measures of technical quality in the health facilities. The paper shows that patients seek facilities that provide high quality consultations and prescriptions, are staffed by more knowledgeable physicians, and are better stocked with basic supplies. Patients avoid facilities that use injections too liberally or over‐prescribe medication. Furthermore, the patterns differ significantly by illness condition and show evidence that patients understand the relative importance of these qualities for the condition from which they suffer.