Although teenage conceptions rates in the United Kingdom (UK) have seen a downward trend recently, it remains imperative that contraceptive services for young people continue to improve. To ensure that evidence-based interventions are sustained in clinical practice, it is useful to assess the experiences of those delivering them. This study explores the experiences of sexual health clinicians who were trained to deliver a one-to-one behaviour change intervention aiming to improve contraceptive use in young women. The intervention was set in a UK NHS contraceptive and sexual health service and involved clinicians’ facilitating (within one-to-one consultations) the formation of implementation intentions (or ‘if-then’ plans) that specified when, where and how young women would use contraception. A focus group was conducted with seven clinicians who had delivered the intervention. A thematic analysis of the focus group revealed three overall themes: (1) How the intervention worked in practice; (2) barriers and benefits to delivering the intervention; and (3) positive changes to individual consultation style and wider ‘best practice’ within the clinic. Our findings show that, with support, clinical staff would be in favour of incorporating if-then planning as a strategy to help promote contraceptive adherence in young women.