AbstractThis study seeks to gauge the mastery levels of the overall basic science process skills (BSPS) and the specific BSPS amongst the Malay and the Orang Asli upper primary students. The 36-multiple-choice-item BSPS Test was administered to a total of 348 years 4, 5 and 6 students from an urban primary school in Malaysia. The analyses were performed descriptively and inferentially utilizing an independent samples ttest and one-way ANOVA. The findings indicated that: (1) the Malay students showed an acceptable mastery level for the skills of classifying (71.12%) and predicting (67.43%); (2) the Orang Asli students failed to show an acceptable mastery level across all the BSPS; (3) there were statistically significant differences in the mastery levels across all the BSPS between the Malay and the Orang Asli students, favouring the former; (4) among the Malays, year 6 students achieved markedly higher than year 4 students in classifying, and that years 6 students achieved markedly higher than.....