In September 2020, a significant increase in the number of COVID-19 clusters in nursing homes (Ehpad) was reported to the Nouvelle-Aquitaine Regional Health Agency (ARS), with a large number of cases reported. A study was conducted to compare the characteristics of nursing homes that reported a cluster based on the attack rate, as well as the control measures implemented when these clusters occurred. A cross-sectional study was conducted in October 2020 among 45 Ehpad facilities in Nouvelle-Aquitaine. Data on facility characteristics, clusters, and the preventive and control measures implemented were collected from four information sources, including an online self-administered questionnaire. Nursing homes that reported a high-impact cluster (infection rate exceeding 30% among residents or staff) were compared to nursing homes that reported a moderate-impact cluster (infection rate below 30%). Of the 45 selected nursing homes, 17 responded to the online survey, including 9 that had experienced a high-impact cluster. Among the latter, the following were notably observed: a higher proportion of staff members under the age of 40, a lower full-time equivalent ratio of paramedical staff to the number of beds, staff with less training in hygiene, fewer single rooms available, later reporting of COVID-19 cases, and longer delays in implementing control measures (results not statistically significant). This study helped guide the Regional Health Agency (ARS) on the factors that may contribute to the occurrence of numerous COVID-19 cases in nursing homes, with the aim of enabling them to identify nursing homes that meet these vulnerability criteria and provide them with greater support. Given the study’s limited scope and the lack of statistical significance, a study covering all nursing homes is currently underway to supplement these initial findings.