Introduction Administration of non-steroidal anti-inflammatory drugs (NSAIDs) before tooth extraction may reduce post-surgical pain, but there is a lack of research.Aims To compare pain and anxiety in paediatric tooth extraction patients receiving a pre-operative NSAID vs placebo.Design Randomised, double-blind, placebo-controlled clinical trial.Setting Princess Nourah bint Abdulrahman University's dental clinic in Riyadh, Saudi Arabia.Materials and methods Eligible paediatric tooth extraction patients were randomised to group A, which received NSAID pre-operatively, or group B, which received the placebo.Interventions A research coordinator measured participants before extraction, and then 3 hours and 24 hours post-extraction.Main outcome methods The Wong-Baker FACES scale and the Modified Child Dental Anxiety Scale (faces).Results There were 56 participants (28 in each group). Pain and anxiety scores were not statistically significantly different between the two groups before or 24 hours post-extraction. However, group A had significantly lower pain (-1.3151, p = 0.0063) and anxiety scores (-0.6071, p = 0.0081) compared to group B three hours post-extraction.Discussion Pre-operative administration of NSAIDs in paediatric dental patients was associated with significantly lower post-extraction pain and anxiety.Conclusions Clinicians should consider making NSAID administration before paediatric tooth extraction part of their clinical protocol.