This study explores whether or not firms with different characteristics engage in open innovation (OI) differently. The aim specifically is to examine how firms differ in engaging in inbound and outbound OI based on their characteristics: type of industry, age, market orientation, firm ownership, size in terms of number of employees and annual revenue. Data were collected from 133 firms operating in various high-tech industries in Malaysia. Results obtained using several one-way analysis of variance (ANOVA) tests show that a firm’s engagement in OI is a function of the type of industry the firm is operating in, its ownership structure and its size in terms of number of employees and revenue earned. However, engagement in OI was not found to be related to firms’ age or their market orientation. These findings shed light on the characteristics of firms that engage in OI more than others, thus having vital implications for theory and practice. The article presents a discussion of these findings along with limitations and future research directions.