During the last 15 years aerobiology has become a relevant branch of allergy, making possible the partial clarification of the relationships between clinical diseases and environment. We performed a 10-year survey of pollen counts and pollen sensitization in a confined area on the western Ligurian coast of Italy in order to evaluate possible changes in aerobiological pattern and to correlate them with the prevalence of sensitization. Pollen counts for the area surrounding Bordighera in the period from 1988-1997 were analyzed; the occurrence of skin sensitization in outpatients were also studied during the same period. We considered the following allergens: Parietaria, grasses, Compositae, Cupressaceae, olive and birch. We also examined the possible differences between patients living on the seaside and those living inland. Over the 10-year period a significant increase in the pollen counts was seen for birch and Compositae (p = 0.001); this was accompanied by a parallel significant increase in the rate of sensitization (p = 0.004 and p = 0.01, respectively). Conversely, an increase in sensitization to Cupressaceae (p = 0.001) and olive (p = 0.03) was also seen, although no change in the pollen counts was detectable. Finally, the prevalence of sensitization to Cupressaceae and Compositae was higher in the patients living in the coastal region than those residing inland. These data suggest that a positive correlation between the pollen counts and the rate of sensitization exists for certain pollens. Nevertheless, for other species such a correlation was not apparent, and additional environmental factors maybe involved in the increased prevalence of sensitization.