OBJECTIVE: To evaluate the economic implications of upper respiratory tract infection to the Nigerian society. METHODS: It involves Cost of Illness analysis among upper respiratory tract infection Out- Patients in Lagos University Teaching Hospital. Data collected from 182 case notes include; demographics, diagnosis, diagnostic tests, no of visits, and prescribed drugs. Direct and indirect costs were included. The costs include, personnel, diagnostic tests, transport and antibacterial cost. The hospital cost of drugs and tests were used. Stop-watch time studies and monthly earnings were used to calculate the personnel costs. Average time spent at each visit and expected earnings were used to calculate the indirect costs. The current hospital costs were used for all calculations hence neither discounting nor inflation was considered. RESULTS: Total cost of drugs =N358,790.00 ($2462.80); Average = N1,971.40($14.10) Personnel cost=N49,156.40($351.12); Average = N270.00($1.93) Diagnostic Test cost = N9,100.00($65.00); Average = N50.00($0.36) Transport cost = N36,930.00($263.80); Average = N202.91($1.45) Indirect cost = N103,350.00($738.21) Average = N567.86 ($4.06) Cost of illness = N557,326.40($3981.10) Average = N3,062.23($21.87). Cost of drugs for each disease condition Acute Otitis media (n=45 = N24,526.00($175.20); Average = N545.02 ($3.90). Chronic Superative Otitis media (n = 37) =N 42,982.00($307.01); Average = N1161.68($8.30)onchopneumonia (n=70)=N257,299.00($1837.85); Average =N 3675.41($26.25)Tonsilitis (n=12)=N14,923.00($106.60); Average = N1243.58($8.90). Other) =N19060.00($136.14) ; Average = N1058.94($7.56). Prevalence of Otitis media in Nigeria = 29.0% in children below 5 years. = 7,772,000 cases (7.7million cases) Average cost of Otitis media = N823.27($5.88) Cost of drugs for 7.7 million cases of otitis media alone = N6,398,454,440.00 (Over N6.3 billion)(>$450million). CONCLUSION: Cost of therapy associated with URTI is enormous. This high cost might be partly due to the use of antibiotics in most cases of URTI, a good proportion of which are viral. The use of treatment guidelines is necessary to ensure a wise use of the limited resources.