Many psychiatric disorders emerge during adolescence. The study of executive functions in animal models of these disorders critically requires short-duration tasks measuring these functions before the animal ages. Here, a novel 5-choice serial reaction time task (5-CSRTT) protocol is presented, to measure attention and impulsivity within one week, without scheduled food deprivation and with little animal handling. Mice were allowed 24-h/day task access from their home-cage, during which they could self-pace task progression and earn unlimited food rewards depending on task performance. Manipulation of task parameters in this self-paced 5-CSRTT protocol (SP-5C) affected attentional performance and impulsivity to a similar extent as previously observed in the 5-CSRTT. Task activity followed intrinsic circadian rhythm, distinctive for the SP-5C protocol, with task performance stable over the day. The sensitivity of the SP-5C protocol to detect strain differences between C57BL/6J, DBA/2 J, BXD16 and BXD62 mice was demonstrated as well as its suitability for testing adolescent mice. Acute administration of the muscarinic acetylcholine receptor antagonist scopolamine impaired attentional performance, providing initial pharmacological validation of the task. The SP-5C substantially shortens the assessment of impulsivity and attention, increases test efficiency and enables the assessment of adolescent mouse models of psychiatric disorders.