Generally, radical innovations are not easily adopted in the market. Potential adopters experience difficulties to comprehend and evaluate radical innovations due to their newness in terms of technology and benefits offered. Consequently, adoption intentions may remain low. This paper proposes bundling as an instrument to address these problems. More specifically, this paper examines how consumer comprehension, evaluation, and adoption intention of radical innovations may be enhanced by bundling such products with existing products. In addition, it is argued that the proposed effects are contingent upon the level of fit perceived to exist between the radical innovation and the product that accompanies it in the bundle. Furthermore, consumers' prior knowledge may affect the influence of bundling on the innovation adoption process as the interpretation of the meaning of new products may be strongly related to prior knowledge. This study therefore investigates whether consumer prior knowledge has such a moderating effect. Hypotheses are tested by means of an experimental study with three different radical innovations and distinguishing among offering the radical innovation separately, offering the radical innovation in a bundle with moderate perceived fit between the products, and offering the radical innovation in a bundle with high perceived fit between the products. Results show that product bundling enhances the new product's evaluation and adoption intention, although it does not increase comprehension of the radical innovation. Moreover, the results show that comprehension, evaluation and adoption intention of the innovation significantly decrease when consumers perceive a moderate fit between the products in a bundle. Taken together, these findings contribute to the bundling literature by showing not only that product bundling may indeed be an effective instrument to introduce a radical innovation but also that product bundling may be counterproductive when ignoring the critical role of perceived product fit as core characteristic of a product bundle. In addition, the notion that product bundling helps to enhance the evaluation and purchase intention of new and relatively complex products suggests a suitable strategy for new product managers to enhance benefits and reduce learning costs for radical innovations. Moreover, the effects of bundling on consumer appraisals of radical innovations are also shown to depend on the level of knowledge respondents possess regarding the product category of the radical innovation. More specifically, if bundled with a familiar product, novices tend to evaluate the innovative product more positively, but for experts no such effect can be detected. As such, these results provide additional specific implications for managers when introducing radical innovations in the market. Offering a radical innovation in a product bundle could be a fruitful strategy for companies that target customers with little or no prior knowledge in the product domain. © 2010 Product Development & Management Association.