Pollen allergies affect 10 to 15% of the general population. A pilot study was conducted in Clermont-Ferrand during the 2000–2001 period to investigate the short-term relationship between daily variations in the number of cases of allergic rhinitis and/or conjunctivitis and daily variations in pollen counts. Data from the Erasme Auvergne database were used to identify all individuals who were dispensed at least one prescription medication for the treatment of allergic rhinitis or allergic conjunctivitis and who were reimbursed by Social Security. A case of allergic rhinoconjunctivitis (ARC) was defined according to the following criteria: residing in the study area, being at least 5 years old, and having, on a given day, been dispensed an oral antihistamine in combination with a topical treatment for allergic rhinitis or allergic conjunctivitis. Eleven allergenic pollens: Betula (Birch), Cupressaceae (Cypress), Quercus (Oak), Platanus (Sycamore), Fraxinus (Ash), Salix (Willow), Alnus (Alder), Corylus (Hazel), Poaceae (Grasses), Artemisia (Mugwort), Plantaginaceae (Plantain), and a control pollen, Pinus (Pine), were studied (source: RNSA). A Poisson regression model was used. This model accounts for temporal variations, air pollution, and meteorological data as confounding factors. On average, 25.5 cases of RCA per day were recorded (range: 0–189) during the study period. A positive and significant association was observed for Birch, Cypress, Oak, Ash, and Grass pollens. Relative risks ranged from 1.03 (95% CI: 1.00–1.05) to 1.22 (95% CI: 1.11–1.35) for an increase of one interquartile range in daily pollen counts for cypress (13 grains/m³) and birch (45 grains/m³), respectively. For the control pollen (pine), no significant association was observed. Although positive associations were observed for most of the allergenic pollens studied, they were significant only for birch, cypress, oak, ash, and grass pollens. Analyses of data collected over a longer period are needed to confirm these results. (R.A.)