This paper describes the development of a diagnostic test to assess teachers' understanding of the learning cycle and highlights common misconceptions identified through the administration of the diagnostic instrument. The Learning Cycle Test was administered to 28 undergraduate students enrolled in elementary science methods who had received instruction on the learning cycle. This paper describes the misconceptions identified through analysis of items on the Learning Cycle Test in the context of exploration, concept introduction, application, and general questions about the learning cycle. Results indicate that elementary science methods students continue to have alternative conceptions about the learning cycle after instruction on the learning cycle. The most common alternative conceptions were centered around the teacher explaining and/or defining the concept prior to or during exploration. The Learning Cycle Test, which appears to provide a feasible approach for evaluating students' understanding and for identifying alternative conceptions about the learning cycle, is included in the paper with percentage of responses by preservice science teachers with specific misconceptions. Contains 21 references. (JRH)