Background: The postoperative length of hospital stay (PLOS) is an important indicator of surgical quality. We identified perioperative factors that affect prolonged PLOS (PPLOS) after laparoscopic colorectal cancer resection, which is the preferred surgical approach for colorectal cancer (the third most common cancer).Methods: This study was a secondary analysis of a randomized trial (PROtective Ventilation using Open Lung approach Or Not) that included 280 patients who underwent laparoscopic colorectal cancer resection. The primary outcome was PPLOS, defined as a PLOS that was longer than the median PLOS. Perioperative factors, including baseline characteristics, anesthesia, and surgical variables, were included in the univariate and multivariate analyses to identify factors influencing PPLOS.Results: The median PLOS was 10 days, and 117 patients had PPLOS. We identified six influencing factors for PPLOS: preoperative pulse oxygen saturation <96% (odds ratio [OR], 3.09 [95% confidence interval [CI], 1.38–6.92]; P = 0.006), tumor metastasis (OR, 0.34 [95% CI, 0.13–0.91]; P = 0.031), Mile’s operation and left hemicolectomy (OR, 4.51 [95% CI, 1.67–12.18]; P = 0.003), perioperative surgical events (OR, 2.44 [95% CI, 1.25–4.76]; P = 0.009), postoperative albumin infusion (OR, 2.19 [95% CI, 1.14–4.19]; P = 0.018), and postoperative early ambulation (OR, 0.35 [95% CI, 0.18–0.68]; P = 0.002). Further stratified analysis also showed that postoperative albumin infusion might be a risk factor for PPLOS, even in patients with a preoperative albumin level <40 g/L (OR, 2.29 [95% CI, 0.98–5.34]; P = 0.056) or duration of surgery ≥3 hours (OR, 2.52 [95% CI, 1.08–5.87]; P = 0.032).Conclusions: A low pulse oximetry reading, complex surgical approach, perioperative surgical events, and postoperative albumin infusion may be predictors of PPLOS after laparoscopic colorectal cancer resection, whereas tumor metastasis and postoperative early ambulation might be protective factors. The association between postoperative albumin infusion (a modifiable factor) and PLOS or clinical outcomes warrants further investigation.