BACKGROUND Hundreds of studies investigating the epidemiology of asthma in various populations have been conducted in the past 30 years, yielding a large body of interesting data, including data on prevalence and risk factors. Less information is, however, available on the accurate diagnosis of asthma and its correct treatment. Epidemiological studies of the prevalence of asthma in the general population was conducted between 1998 and 2000 in the Lodz Province in Poland. The present analysis is an evaluation of the detectability and treatment of this disease. METHODS The study group consisted of 1522 randomly selected residents of the Lodz Province aged 3 to 80 years. The demographics and medical history were collected using standardised questionnaires. All the respondents underwent skin prick tests and screening spirometry. Additional diagnostic tests were performed in doubtful cases. RESULTS Complete data collected from 1340 subjects (1057 adults and 283 children) were included in the analysis. The prevalence of asthma was calculated at 7.3% in adults and 8.5% in children. The accurate diagnosis of asthma had not been made in 71% of symptomatic children and 49% of the adults. Forty-eight percent of adult asthmatics had not used any antiasthmatic medication in the previous 12 months. Subjects suffering from asthma had most commonly used the following drugs in the previous 12 months: beta(2)-agonists (46.8%), anticholinergics (13%), inhalation glucocorticoids (36.4%), oral glucocorticoids (16.9%), parenteral glucocorticoids (3.9%), xanthine derivatives (33.8%) and cromones (11.7%). CONCLUSIONS The results of this study reveal shortcomings in the healthcare system which require appropriate actions aimed at early diagnosis and improvement of allergy treatment before the patient's health deteriorates irreversibly.