Firms can enhance product innovation performance by continuously staying in touch with customers and the market in general. While studies on market oriented product development have identified several general dimensions of market knowledge used in product innovation, the nature of market knowledge that is specifically important in the chemical industry remains unclear. Because firm relevant knowledge resources are increasingly seen as being industry specific, filling this gap becomes more relevant. This study uses a multiple case study of six product innovation projects in six different companies to identify important market knowledge dimensions in the product development of chemical firms. Aggregated results from the six cases point to segment knowledge, application knowledge, product usage knowledge, and customer knowledge as being important market knowledge dimensions. Implications for theory and practice as well as avenues for further research are included.