Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently prescribed drugs for cancer pain. We used the Delphi methodology to evaluate the opinions of clinicians on NSAIDs and paracetamol, with a specific focus on their safety profile. Consensus was reached on seven statements. A high level of consensus was reached regarding the use of NSAIDs and gastrointestinal, cardiovascular, and renal risk in patients taking low-dose aspirin and assessment of liver function during long-term treatment with paracetamol. Consensus was also reached that assessment and monitoring of eGFR are important in the elderly being administered NSAIDs. It was further agreed that NSAIDs can often play a key role in association with opioids in the treatment of cancer pain and that paracetamol is the analgesic of first choice for patients with mild chronic pain. When NSAIDs are administered in combination with steroids, it was agreed that the risk of gastrointestinal damage is increased since steroids delay the healing of ulcers and that paracetamol can be used during pregnancy and does not affect the health of the fetus. This Delphi study highlights that there is poor agreement on how these drugs are routinely prescribed. However, a consensus was reached for seven key statements and may represent a valid contribution to daily practice.