<p>This study examines the impact of a 90-h apprenticeship on Thai preservice science teachers’ confidence and understanding of nature of science (NOS). Twenty-eight participants, specializing in physics, chemistry, biology, or general science, engaged in a hands-on apprenticeship under practicing scientists. To evaluate NOS, pre- and post-apprenticeship assessments were conducted using a 5-point Likert scale to measure participants’ confidence in NOS tenets, while the VNOS Form C, which focuses on understanding of NOS tenets, was administered only post-apprenticeship<i>.</i> Pre-apprenticeship, participants exhibited moderate confidence in NOS, particularly in areas related to creativity and the socio-cultural aspects of science. After the apprenticeship including reflective discussion, significant improvements were observed. Post-apprenticeship survey results showed strong agreement across all NOS tenets, with mode values of 5 and significantly reduced quartile ranges (IQRs), indicating greater consensus among participants. A Wilcoxon signed-rank test revealed that participants’ median total score was significantly higher than the threshold score of 12 (<i>V</i> = 133.5, <i>p</i> = 0.0067), indicating enhanced NOS comprehension. These findings suggest that experiential learning, such as apprenticeships, plays a critical role in shaping preservice teachers’ confidence and understanding of NOS by bridging theoretical concepts with real-world scientific practices. This study emphasizes the need for integrating both authentic scientific experiences and explicit NOS discussion in teacher education programs to foster a well-rounded understanding of nature of science.</p>