Practical investigations are an essential part of formal assessment in Physical Sciences in the South African Curriculum and Assessment Policy Statement (CAPS). In rural schools, individual and group works are frequently used in practical investigations. However, it is not clear from existing literature which of the two methods is more effective in enhancing learners‘ development of Integrated Science Inquiry Skills (ISIS). The purpose of this study was to compare the effectiveness of individual and group practical investigations in the development of ISIS. The research involved 319 purposively selected grade eleven Physical Sciences learners in an educational district in Limpopo Province, South Africa. A mixed-method research approach, primarily involving an experimental comparative design was used to collect quantitative data. Two groups of learners were exposed to either individual or group practical investigations. Pre and post-tests were used to assess learner performance in ISPS. A comparison of the post-test mean performances of the two groups of learners showed no significant difference in their competence in ISPS. The qualitative findings complemented the quantitative data. The implication of the study findings is that, the two teaching approaches used had the same effect on learners‘ development of ISIS.