INTRODUCTION: Colorectal cancer screening programmes have been shown to reduce incidence and mortality. High-risk adenomas (HRA) are the most frequently diagnosed lesions in these programmes, and these patients are referred to a specialist. However, few studies have evaluated the adherence of HRA patients to the recommended endoscopic follow-up. OBJECTIVES: To analyse follow-up adherence and duration in patients diagnosed with HRA in a screening programme. METHODS: Retrospective cohort study of patients diagnosed with HRA within one of the participating hospitals of the colorectal cancer screening programme of Barcelona, during the first round of the programme (2010-2011). The follow-up period was 75.5 months. Descriptive analyses, logistic regression and survival models were performed. RESULTS: 602 patients were included in the study, 66.6% of which were men. The adherence rate was 83.7% (n=504). Follow-up colonoscopy was performed within the recommended time (36±6months) in 57.7%, with a mean follow-up of 34 months. The Cox regression only showed differences at the socioeconomic level, with a lower adherence rate in the most deprived quintile (HR 0.70; 95% CI, 0.53-0.93). CONCLUSIONS: Compared to previous studies, the follow-up adherence rate is considered to be acceptable. However, follow-up was not performed within the recommended time frame in a high proportion of cases. There is a need to further explore the reasons leading to lower follow-up adherence in the most deprived socioeconomic group and to increase the equity of the programme beyond participation.