To determine acute analgesia by acetylsalicylic acid (ASA) when combined with pseudoephedrine (PSE) in patients with upper respiratory tract infection (URTI), we used the sore throat pain model to measure single-dose effects of ASA 500 mg/PSE 30 mg, ASA 1000 mg/PSE 60 mg, and acetaminophen (APAP) 1000 mg/PSE 60 mg (serving as a positive control). Under double-blind, randomized, placebo-controlled conditions, 640 adult patients with confirmed acute pharyngitis and rhinosinusitis associated with URTI rated throat pain intensity and relief at intervals over 6 hours. Efficacy was demonstrated for both doses of ASA/PSE compared with placebo for all end points, including total pain relief and summed pain intensity differences, beginning at 20 minutes on both scales (all P < .05), and the efficacy of APAP/PSE compared with placebo was confirmed (P < .01). Greater differences in pain relief and intensity were also demonstrated between the higher and lower doses of ASA/PSE (P < .05), in particular, among 329 patients with severe pain, as well as between ASA 1000 mg/PSE 60 mg and APAP 1000 mg/PSE 60 mg (P < .05). No serious adverse events were reported. This study demonstrates that ASA is a well-tolerated and effective analgesic in 500- and 1000-mg doses when combined with pseudoephedrine.