The present study focused on the knowledge about the nature of science and the question of the extent to which this knowledge could be explained by employing scientific knowledge, as well as attitudes towards science learning. We obtained data from 171 Spanish pre-service primary school teachers on their knowledge about: a) science concepts, b) science process skills, c) the nature of science (that was split into science construction and validation and the role and function of scientific models), and d) their attitudes towards science learning. Quantitative and qualitative analyses provided interesting results: a) there were significant correlations between any pair of scores of conceptual knowledge, procedural knowledge and attitudes towards science learning; b) knowledge of scientific models elaboration and validity was significantly predicted by scientific conceptual knowledge; c) knowledge of science construction and validation was not predicted by scientific knowledge (concepts and processes) or attitudes; d) only 22.7% of all the participants showed coherent ideas aligned with the currently accepted scientific epistemology; and e) having vast scientific knowledge (concepts and processes) and also good attitudes toward science learning did not guarantee correct ideas regarding science construction and scientific models. We conclude that specific content about the nature of science should be explicitly included in pre-service teachers' curricula, as it is not implicitly provided by other types of scientific content.