The operating room (OR) is a high-cost and high-revenue area in a hospital comprising extremely complex process steps to treat patients. The perioperative process quality can be optimized through an efficiency-oriented central OR management based on performance indices. However, during the COVID-19 pandemic with the corresponding OR restrictions, there was a significant nation- and worldwide decline in the performance, which may have a lasting impact. Therefore, we proposed the hypothesis that COVID-19 pandemic-related OR restrictions could reduce operative performance in the long term. A retrospective, descriptive analysis of perioperative processing times was conducted exemplarily at the University Hospital Ulm using a pre-post design, examining the corresponding second quarters of 2019 to 2022. In total, n = 18,489 operations with n = 314,313 individual time intervals were analyzed. The statistical analyses included the Kruskal-Wallis test adjusted for multiple testing, and the significance level was set at p < 0.01. The results revealed not only a significant decrease in the case volume by 31% (2020) and 23% (2021) during the COVID-19 crisis years, but also significant time delays in various process steps; e.g. the median patient's OR occupancy time (column time) rose from 65min (2019) to 87min (2020) and remained elevated (72min in 2021 and 74min in 2022, respectively). Even in 2022, beyond the pandemic, the net anaesthesia time was permanently enhanced by 9min per case. Furthermore, both, the incision-to-closure time and surgeon attachment time were each significantly prolonged by 7 additional minutes, and the time from the end of anaesthesia to the release of the next patient was extended by 4min. Selected standardized index operations showed only a trend towards these changes, even with a decrease in the incision-to-closure time over time. Overall, long-term changes were found in essential perioperative process times even after retraction of the COVID-19 restrictions, indicating some processual "slow down" after the Covid-19-induced "shut down". Further analyses are needed to determine the appropriate targeted control measures to improve processing times and increase the process quality.