A system may identify a set of items depicted within a set of images, where the set of items are associated with a first product category and a second product category of an online marketplace. The system may determine a complementary category relationship between the first and second product categories based on a relative frequency that items associated with the first and second product categories are depicted together within the set of images. The system may receive a query image depicting a query item associated with the first product category, and may utilize the complementary category relationship to identify and recommend items of the second product category that are complementary (e.g., visually and stylistically complementary) to the query item.