A search engine system displays the results of a multiple-category search according to levels of relevance of the categories to a user's search query. A query server receives a search query from a user and identifies, within each of multiple item categories, a set of items that satisfy the query. The sets of items are used to generate, for each of the multiple categories, a score that reflects a level significance or relevance of the category to the search. The scores may be based, for example, on the number of hits within each category relative to the total number of items in that category, the popularity levels of items that satisfy the query, a personal profile of the user, or a combination thereof. The categories are then presented to the user, together with the most relevant items within each category, in the order of highest to lowest category relevance.