In Africa antimalarials are often prescribed when malaria is unlikely, a problem that is becoming critical as more expensive antimalarials replace established drugs. However, little is known about what drives the overuse of antimalarials. We conducted this study to explore to what extent current prescribing behavior in hospitals is driven by patient demand. Methods Consultations were observed followed by exit interviews with patients or caretakers. Five district hospitals where microscopy was routinely available were selected in areas of low (n¼3) and high (n¼2) malaria transmission in northeastern Tanzania. All outpatient consultations during the study period were observed (n¼669). Those sent for a malaria blood slide or treated with antimalarials presumptively were interviewed (n¼326). At the end of the study, clinicians were interviewed for their opinions on the use of antimalarials. Findings Patients were not observed to demand antimalarials from clinicians, but occasionally asked for a malaria slide. Patient satisfaction on exit was similar between those prescribed antimalarials and those not prescribed antimalarials, but more patients or carers expressed satisfaction when the patient had been tested than when not. Clinicians rarely reported perceiving patient demand for antimalarials and asserted that such demand for medication would not affect their prescribing behaviour. Conclusions Patient demand was not found to be driving the over-prescription of antimalarials found in the hospitals in our setting. To the contrary, the involvement of patients may provide an opportunity to improve prescribing practice if their expectations for testing and treatment in line with test results can be effectively communicated to clinicians.