Aim: To study the influence of pineapple juice on the pharmacokinetics of celecoxib and montelukast in humans. Experimental methods: The research comprised two separate arms. Each arm was randomized, two-crossover periods separated by a 2-week washout period. Subjects received a single dose of celecoxib or montelukast after pretreatment with either water or pineapple juice for 4 days before the study beginning. Results & conclusion: Pineapple juice enhanced the systemic exposure of both drugs without any noticeable adverse effects. For celecoxib, Cmax and AUC0–∞ were increased significantly by 40 and 60%, respectively. Cl/F was decreased by 45% without affecting its t1/2. For montelukast, Cmax and AUC0–∞ were significantly increased by 21 and 48%, respectively, along with 25% decrease in clearance and 13% increase in t1/2.