Although hands-on laboratory experiments are traditionally used in schools, virtual laboratories have entered today's classrooms, due to their specific affordances. In this study, we compared the effect of using hands-on and virtual laboratories in isolation to two different combinations on middle school (7th grade) students' acquisition of conceptual knowledge and inquiry skills. Our findings indicate that using hands-on and virtual laboratories sequentially instead of in isolation gives better results for students' acquisition of knowledge and inquiry skills. This result, together with similar findings from other studies, suggests that virtual and hands-on laboratories may have complementary affordances. In the current study, no advantage was seen for either of the two different combinations used.