Acute bacterial conjunctivitis is a prevalent infection in the population. Topically applied chloramphenicol has been the most frequently used treatment on this indication. The recommended dosage of 0.5% eye drops has been one drop hourly/every two hours for three days, thereafter every 4-6 hours. This dosage is not based on scientific documentation. We have conducted a clinical trial in general practice to compare the standard dosage with a simplified dose regimen. 77 patients were allocated to the regimen described above and 75 patients were instructed to use the drops four times a day. Mean duration until complete healing of all symptoms was 4.4 days (median 4; 95%-confidence interval (CI) 4-5) and 4.8 days (median 5; CI 4-5) in the two groups. The proportion of completely cured patients after nine days of treatment was 95% and 88% respectively; after four days corresponding percentages were 61% and 44% (p < 0.05). For other clinical variables the differences were small and not statistically significant. Compliance was significantly better for the simplified regimen (p < 0.001). The study indicates that the simplified dose regimen may be preferable in clinical practice.