Textbooks play a significant role in education around the world. Although several studies have reported that textbook-led teaching and learning suggests a teacher-centred content approach, textbook use is prevalent in the teaching and learning culture of Bangladesh. The redeveloped primary science textbooks of Bangladesh now promote the teaching of a student-centred inquiry-based approach. This study explored the inquiry process skills promoted by the primary science textbooks and the voice of textbook professionals (authors and publishers)--their intentions behind the pattern of promotion of the inquiry process skills. A qualitative content analysis of three primary science textbooks was accompanied by interviews with textbook professionals. Results showed that the inquiry process skills of observing, recording data, and communicating results received the highest emphasis in and across the textbooks. Textbook professionals valued students' scientific understanding of their world through the development of their inquiry process skills, and showed adaptive expertise, to varying degrees, as they designed the three textbooks. The students' context, cognitive development, and learning processes were found to be key considerations in the design features of the textbooks.