Purpose: Critical thinking and student attitudes are pertinent to 21st century learning of cultural values which is still very low. Research with a focus on improving these skills and attitudes using inquiry-based approaches are very limited. This research aimed to improve critical thinking and student attitudes of elementary school teacher education students with an inquiry-based learning model assisted by the ethno-constructivism module against the traditional printed teaching materials used in lectures. Methodology: This study used experimental quantitative design where the sample was selected using the purposive sampling technique. The sample of 68 participants was equally divided into one experimental group (n = 34), who was taught by the inquiry-based learning model and one control group (n = 34), taught using traditional teaching materials. Oliver-Hoyo Rubric for Critical Thinking (OHRCT) and one attitude questionnaire were used as research instrument. Data was analyzed using SPSS 21 application to achieve descriptive statistics in the form of mean, min, max, and categories and inferential statistics for independent sample t-test (t-test). Findings: A significant difference in terms of critical thinking skills and students' attitude was found between the control and the experimental groups. The experimental group treated through the inquiry-based ethno-constructivism module was found having superior critical thinking skills and attitudes towards learning cultural values as compared to the students of control group. Implications for Research and Practice: The implementation of inquiry-based learning model assisted by the ethno-constructivism module is proven as an effective method to encourage critical thinking and developing positive attitude among elementary school teacher education students. Pre-service teachers need to be given the opportunity to develop direct experiences and thoughts about cultural values and devise activities to teach these values. The teachers must also introduce the inquiry-based learning in developing their teaching tools.