A method of organising content items includes obtaining information (19-21) associating each of a first and at least one further label with respective sets of first content items. At least one first content item is associated with the first label in response to user input. A second content item is obtained. For each of the first and further labels, a similarity measure is calculated between a feature vector characterising the second content item and each of the feature vectors characterising first content items associated with the label. The first label is associated with the second content item upon determining that the second content item is similar to the first content items associated with the first label, according to calculated values of the similarity measure.