Abstract Aims MitraClip therapy for the treatment of functional mitral regurgitation (FMR) is an increasingly used intervention for high-risk surgical patients. The aim of this observational study was to assess the impact of residual mitral regurgitation (rMR) at discharge on long-term outcome after MitraClip therapy in patients with FMR. Methods and results Overall, 458 patients (mean age 73.8 ± 8.9 years) underwent MitraClip implantation between September 2008 and December 2017. The impact of rMR ≤ 1+ at discharge (n = 251) was retrospectively compared to patients graded as rMR 2+ (n = 173) and rMR ≥3+ (n = 34) at discharge. Median follow-up time was 5.09 years (5.00–5.26) with maximum follow-up of 10.02 years. The primary outcome was survival, and Kaplan–Meier analyses revealed significant differences among all rMR subgroups with highest survival rates for rMR ≤ 1+ patients. This was further confirmed by composite outcome analyses (P < 0.02). The inferior outcomes of rMR 2+ and rMR ≥ 3+ at discharge were confirmed by increased adjusted hazard ratios when rMR 2+ (1.54, P = 0.0039) and rMR ≥ 3+ (2.16, P = 0.011) were compared to rMR ≤ 1+. Moreover, patients with stable rMR ≤ 1+ grades within 12 months showed significantly higher survival rates compared to patients with rMR ≤ 1+ at discharge and rMR ≥ 2+ at 12-month follow-up or rMR ≥ 2+ at discharge and 12-month follow-up (P = 0.029). Conclusions Patients with optimal and durable rMR ≤ 1+ at discharge and 12-month follow-up showed better outcome compared to patients with rMR 2+ and rMR ≥ 3+. Treatment success and durability characterized by rMR ≤ 1+ at discharge and 12 months seem to be important factors for long-term outcomes, which has to be further confirmed by prospective randomized trials.