BACKGROUND Immunofluorescence (IF) has been used in many laboratories for virus diagnosis but has begun to fall inappropriately out of favour as a diagnostic method as pressure on budgets and for objective quality control increases. OBJECTIVE To review the status, value and benefits of IF. CONCLUSIONS IF has, we believe, still a valuable role to play in routine virus diagnosis because it is rapid, accurate (with properly validated reagents), flexible and, by giving feedback on the quality of the specimens collected, promotes dialogue with the customer clinicians to their benefit and to that of the diagnostic laboratory. These benefits are not easily duplicated by other methods or techniques. While such rapid diagnosis primarily benefits the individual patient, providing results within a clinically relevant time has a secondary effect of increasing use of the service. It is our experience that the availability of rapid IF diagnosis (as opposed to culture or serology) for respiratory viral infections leads to a substantial increase in its use, thereby enhancing the amount and breadth of the resultant epidemiological data.