Abstract: This invention relates to the prefetching of content items, for example, prefetching of videos, to make the content items accessible from a local data store (118) of the mobile device (112). A processor (114) determines for each of the multiple content items a benefit value associated with an access time. The processor (114) also determines for each of the multiple content items an estimated prefetching cost associated with a prefetching time. Then, the processor (114) selects one of the multiple content items for downloading at the associated prefetching time based on the benefit values and the prefetching cost at the prefetching time. This way, the prefetching can be managed such that the most useful content item which the user will likely access soon are downloaded while at the same time minimising the cost.