A pragmatic classification. Rare diseases (RD) might be a research target on primary care because their gift of scientific knowledge building. A rational scheme would be necessary for clinical and scientific findings. Retrospective long-term report of the most important RD achieved for a ten years period by a general practitioner at a non-urban primary care facility (Andalusia-Spain). Our results are classified as: a) rare adverse drug reactions (RADR); b) accurate RD diagnosis (RDD); and c) RD prevalence study (RDP).