Aim of the study. To estimate timeliness of diagnosis of 2-type diabetes and causes of complications in Prienai district. Methods. In January – December 2005, questionnaire survey of the residents of Prienai district, to whom 2-type diabetes (n=76) was diagnosed for the first time and patients suffering of 2-type diabetes (n=219), was conducted. Statistical analysis package SPSS (9.0) was used to analyse the data. Dependence of two symptoms was researched by the use of Chi-Square test (χ²). Zero hypothesis was rejected, when p<0,05. Results. Diabetes was untimely diagnosed for 62,7 % patients, because at the moment of diagnosis they already had chronic complications, and 37.3% patients had their illness diagnosed in time. In cases when patients visited a health care institution for preventive reasons, diabetes was diagnosed more frequently and in a lighter stage than in the cases when patients addressed health care institutions due to complaints. If a family doctor suspected diabetes, diagnosis was timely diagnosed more frequently than if suspected by any other specialist. According to statistics, complications were caused by duration of illness, insufficient use of self-control means. Timeliness of diagnosis and rise of complications of diabetes did not depend on the age, sex, place of residence, marital status, education or occupation of the respondents. Conclusions. Timeliness of diagnosis of diabetes was determined by timeliness of glycaemia test, reason of a visit... [to full text]