Introduction-Ambrosia elatior pollen sensitivity can lead to respiratory diseases such as rhinitis, asthma and allergic conjunctivitis. Ambrosia is quite an important source of pollen and it is thought to be an invasive plant. Sensitivity prevalence to Ambrosia pollen varies from one country to another. The aim of the present study was to assess the prevalence of pollen allergic rhinitis caused by Ambrosia elatior in the Oltenia area located in the south west part of Romania. Material and method - The study was carried on 1004 patients with allergic rhinitis. All the patients experienced symptoms of allergic rhinitis, associated with /without conjunctivitis or asthma, and positive skin tests to aeroallergens. Results - In the group under study, 48,80% of the cases are sensitized to Ambrosia elatior pollen. The number of patients with allergic rhinitis and pollen sensitivity to Ambrosia is higher in 2014-2015 compared to 2012, i.e. 282 cases and the symptoms are moderate-severe. Conclusions - Ambrosia elatior pollen has become a major source of aeroallergen in Oltenia area.