To investigate tissue features and interproximal contour of posterior implant-supported single crowns (ISSC), which correlate with food impaction. 2) To evaluate the influence of food impaction on the health of the adjacent peri-implant tissue and patients' oral health-related quality of life (OHRQoL).Patients with posterior ISSC under maintenance between July 2019 and July 2020 were recruited. OHRQoL of patients who self-reported food impaction between ISSC and teeth was evaluated by Oral Impacts on Daily Performance questionnaire and reported at patient level. Interproximal prosthesis contours and periodontal/peri-implant tissue conditions were assessed by clinical and radiographic examination. Differences between food impaction (FI) and non-food impaction (NFI) sites were analysed.Totally, 178 patients (286 ISSC and 410 interproximal spaces) were included. Among 119 patients who self-reported food impaction, 84 (70.6%) reported their OHRQoL to be affected with minor-to-severe intensity. The most commonly affected daily performance was the ability to clean the teeth. Plaque accumulation at ISSC, deeper probing depth, complete interdental papilla fill, loose contact, longer contact length, lower contact point level, closer distance between ISSC and tooth, lesser embrasure surface area, tissue-level implant and cement-retained restoration were found significantly more in the FI group than the NFI group (p < .05).Interproximal features of the implant prosthesis were associated with food impaction between the ISSC and the adjacent tooth, which might affect periodontal and/or peri-implant tissue health conditions. Patients' OHRQoL was commonly affected by food impaction, but the intensity was low.