We assessed end-user practice for numerous procedural steps of two types of RDTs: Core Malaria Pf (the cassette format) and OptiMAL IT (the dipstick format). Two types of errors occurred: generic errors common to both types of test and specific errors caused by the test design and manufacturer's instructions. End-user errors were more frequent with OptiMAL IT than Core Pf tests. To improve malaria diagnosis with rapid tests, users require training and better manufacturer's instructions that take into account local conditions.