The benefits of concomitant tricuspid annuloplasty (TAP) for non-significant functional tricuspid regurgitation (TR) during mitral valve replacement (MVR) are controversial. We evaluated the long-term outcomes-particularly the long-term tricuspid valve (TV) functional outcomes-of MVR with or without tricuspid ring annuloplasty. From 2004 to 2014, 256 patients (56.4 ± 12.1 years) with trivial or mild functional TR who underwent MVR were enrolled. Eighty-two patients underwent concomitant tricuspid ring annuloplasty (TAP group), and 174 patients did not undergo the TV procedure (nTAP group). Propensity score-matched analysis was performed (n = 72 in each group). The follow-up duration was 77.4 ± 42.4 months. The early clinical outcomes were similar between the 2 groups before and after propensity score matching with an early mortality rate of 3.5% (9 of 256). No patients experienced ring-related complications during follow-up. Eleven (6.3%) patients developed significant TR (≥moderate) in the nTAP group, while no patients developed significant TR in the TAP group. There were no significant differences in overall survival between the 2 groups before or after matching. However, propensity score-matched analysis revealed that the freedom from significant TR aggravation and freedom from TV-related event rates were significantly higher in the TAP group than in the nTAP group (P = 0.047 and P = 0.043, respectively). Patients with untreated trivial or mild functional TR accompanied by mitral valve disease can develop significant TR during follow-up. TV ring annuloplasty can be performed without complications and can be beneficial for patients with trivial or mild functional TR who are undergoing MVR.