The primary aim of this study was to compare differences, if any, in missed infection prevention and control (IPC) activities before and after the pandemic, along with the related predictors. The secondary aim was to identify relationships between missed IPC activities and unfinished nursing care. A repeated cross-sectional design was conducted in 2019 (pre-pandemic, 184 nurses) and 2024 (post-pandemic, 240 nurses) in a large academic hospital following the Checklist for Reporting of Survey Studies guidelines. The Missed Nursing Care in Infection Prevention and Control Survey (MNC-IPC) (Part A: missed activities, Part B: reasons), the Unfinished Nursing Care Survey (UNCS), and professional data were collected homogeneously across both periods. Self-reported missed IPC activities decreased from 2.15 out of 5 (95% confidence interval (CI), 2.05-2.25) to 1.51 (95% CI, 1.45-1.58) (P<0.0005), as did the related reasons, which decreased from 2.35 out of 4 (95% CI, 2.24-2.46) to 2.20 (95% CI, 2.11-2.30) (P=0.046). The total variance in the MNC-IPC overall scores was explained by 22.8% (pre-) and 20.7% (post-pandemic) by different predictors: system-level issues (estimated value 0.409, P=0.008) and nurses' intention to leave (0.107, P=0.023) in the pre-pandemic and by the number of patients admitted in the last shift (0.015, P=0.053), organizational issues (0.186, P<0.0005) and priority-setting issues (0.092, P=0.053) in the post-pandemic period. MNC-IPC and UNCS scores have reported significant correlations in both periods. Missed IPC activities were less likely in the post-pandemic period possibly due to system efforts and lessons learned during the pandemic, which may have routinized IPC practices among nurses. Overall, predictors of missed IPC care changed after the pandemic, suggesting new patterns and the need for innovative interventions, particularly at the unit level and targeting younger nurses. The correlations between UNCS and MNC-IPC suggest that targeted improvements in one area are likely to yield positive outcomes in the other. However, despite their commonalities, these represent two distinct phenomena.