Background: Interventional radiology plays a major role in oncology both for curative and palliative treatment, but few reports address post-procedural pain. The purpose of this study was to quantify postoperative pain after interventional radiology procedures in oncology and to identify major pain-associated pre and intraoperative factors. Methods: From 2015 to 2019, all patients treated with interventional radiology were included retrospectively in a cohort study. Anesthetic protocols were standardized by the type of radiological procedure. Demographic data, preoperative treatments, analgesic agents, pain score levels, and morphine consumption from the post-anesthesia care unit (PACU) to hospital discharge were collected from databases. In an additional case-control study, patients reporting strong or intolerable pain in PACU were compared to those with no pain. Matching to control cases was based on the type of intervention, sex, and age. Results: From 4411 procedures, severe pain in PACU was more frequent in women (p < 0.04) and the youngest patients (p < 0.0001), after general anesthesia (p < 0.0001). Higher pain levels were associated with certain procedures, such as arterial embolization, limb cementoplasty, osteosynthesis, and abdominal tumor ablation, and when the intervention duration exceeded 160 min (p = 0.038). In the cohort study, high-dose remifentanil (≥0.055 µg/kg/min) was a risk factor for post-procedural high pain levels (p < 0.001). Intraoperative ketoprofen was associated with a decrease in high pain level incidence (p < 0.0001). Severe pain in PACU was a risk factor for severe pain in wards from day 0 until discharge. Conclusion: Severe pain depends on the type and duration of interventional radiology, type of anesthesia, and preoperative use of opiates. Limiting doses of remifentanil and injecting intraoperative analgesics, especially ketoprofen, may reduce the incidence of post-intervention severe pain.