Background The role of dual-modality drainage of walled-off necrosis (WON) in patients with acute pancreatitis (AP) is established. However, there are no data on the association of clinical outcomes with the timing of percutaneous catheter drainage (PCD). We investigated the impact of the timing of PCD following endoscopic drainage of WON on clinical outcomes in AP. Materials and Methods This retrospective study comprised consecutive patients with necrotizing AP who underwent endoscopic cystogastrostomy (CG) of WON followed by PCD between September 2018 and March 2023. Based on endoscopic CG to PCD interval, patients were divided into groups (≤ and >3 days, ≤ and >1 week, ≤ and >10 days, and ≤ and >2 weeks). Baseline characteristics and indications of CG and PCD were recorded. Clinical outcomes were compared between the groups, including length of hospitalization, length of intensive care unit stay, need for surgical necrosectomy, and death during hospitalization. Results Thirty patients (mean age ± standard deviation, 35.5 ± 12.7 years) were evaluated. The mean CG to PCD interval was 11.2 ± 7.5 days. There were no significant differences in baseline characteristics and indications of CG and PCD between the groups. The mean pain to CG interval was not significantly different between the groups. Endoscopic necrosectomy was performed in a significantly greater proportion of patients undergoing CG after 10 days ( p = 0.003) and after 2 weeks ( p = 0.032). There were no significant differences in the complications and clinical outcomes between the groups. Conclusion The timing of PCD following endoscopic CG does not affect clinical outcomes.