Neurotransmission represents a key concept in the history of biology. The objective of this study is to elicit Moroccan university students? conceptions of neurotransmission and highlight potential difficulties and obstacles that may hinder its effective learning. A questionnaire was administered to 120 science students as a pre-test. After the neurotransmission course at Dhar El Mahraz Faculty of Science, the same questionnaire was re-administered. The results of the study appeared that the majority of the science students had deficiencies at integrating and assimilating the concept of neurotransmission and other related concepts.