The current study compared the effectiveness of two methods in biology teaching that are based on the science-as-inquiry approach: visits to authentic university laboratories (AULs) and analyzing adapted primary literature (APL). The methods' effectiveness was measured in terms of high-school students' increased understanding following a 6-week intervention that emphasized five major aspects of the nature of science (NOS): the tentativeness of scientific understanding, the cooperative nature of the scientific process, methodological diversity, the sociocultural embeddedness of scientific knowledge, and the aims of scientific inquiry. A quasi-experimental, pre-post control design was applied, utilizing quantitative evaluation methods. Findings indicate that teaching NOS in biology high-school classes using science-as-inquiry methods is an effective approach for enhancing NOS understanding. Both of the proposed methods appear to be promising; however, the AUL method was found to be more effective for enabling advanced-level high-school biology students' understanding of these NOS aspects. In conclusion, both AUL and APL are potentially effective methods that can be adapted for teaching various biology subjects in different cultural contexts.