Post-tonsillectomy pain can be severe. We investigated the analgesic effect from combinations of paracetamol, pregabalin and dexamethasone in adults undergoing tonsillectomy. In this randomized double-blind study, 131 patients were assigned to either group A (paracetamol+placebo), group B (paracetamol+pregabalin+placebo) or group C (paracetamol+pregabalin+dexamethasone). Pre-operatively, patients received either paracetamol 1000 mg, pregabalin 300 mg, dexamethasone 8 mg or placebo according to their allocation. Post-operative pain treatment included paracetamol 1000 mg 4× and ketobemidone 2.5 mg p.n. Ketobemidone consumption, pain scores [visual analogue scale (VAS)], nausea, sedation, dizziness, number of vomits and consumption of ondansetron were recorded 2, 4 and 24 h after the operation. P<0.05 was considered statistically significant. The mean 24-h VAS-pain score at rest was reduced in group C (P<0.003) vs. group A. The mean 24-h VAS-pain scores during swallowing were reduced in group B (P=0.009) and group C (P<0.003) vs. group A. Consumption of ketobemidone (1-4 h post-operatively) was lower in group B (P=0.003) and group C (P=0.003) vs. group A. The mean 24-h dizziness score was higher in group B (P<0.003) and C (P=0.003) vs. group A. Other parameters including re-operation for post-tonsillectomy bleeding were not different between groups. Pregabalin and pregabalin+dexamethasone reduced post-operative pain scores and consumption of ketobemidone following tonsillectomy. Dizziness was increased with pregabalin.