Background Allergic disorders are common ailments, which cause socioeconomic problems. The aim of the study was to determine the prevalence of allergic disorders and symptoms suggestive of asthma in Mashhad city, Northeast Iran. Methods We performed a cross-sectional survey in a randomly selected representative sample of the Mashhad population. A questionnaire was used based on the standard questionnaire of the European Community Respiratory Health Survey (ECRHS). The questionnaires asked about allergy-related symptoms including nasal symptoms, eye symptoms, atopic dermatitis symptoms, confirmed asthma, asthma-related symptoms, and nonspecific allergic symptoms. Some of the environmental triggers of allergic reactions such as pollen, dried plant, dust, drugs, food, fruit, condiments, makeup, perfume, jewelry, latex gloves, and keeping a pet were considered in the questionnaire. Results The prevalence of allergic disorders in this study was found to be 27.5% in the city of Mashhad. According to our definitions, the rates detected of allergic rhinitis, atopic dermatitis, conjunctivitis, rhinoconjunctivitis, and asthma were 22.4, 6.6, 13.5, 9.5, and 2.3%, respectively. Half of the allergic group suffered from rhinorrhea and other symptoms were significantly higher than in the nonallergic group. Dust and pollen were found to be the most important triggers of allergic reactions in the allergic group. Conclusion This report may be useful to understand the factors contributing to asthma and allergic disorders and may help in management and control of these problems.