There is clear evidence diagnosis of malaria in much of Africa is sub-optimal and this has a negative impact on patient care. Many of those treated for malaria do not have it. Rapid diagnostic tests (RDTs) are dipsticks which diagnose malaria rapidly and accurately. The main objective of this trial is to determine by means of a randomised trial the impact of introducing RDTs into a standard outpatient setting in Tanzania has on the appropriate prescription of antimalarials. Other objectives are: