For several years the German healthy child clinics program has been a highly appreciated preventive measure and is subject to constant development. However, attendance depends on the families' sociodemographic situation. Findings are documented in a medical checkup booklet (the so-called Gelbes Heft). Currently, there is no procedure to use the data collected for epidemiological purposes nor to evaluate the pediatric prevention measures in Germany.  Between 2011 and 2016, we recruited 3480 study participants for our population-based cohort study LIFE Child in Leipzig. 90.6 % submitted their check-up booklets which were subsequently scanned, the data was digitalized and transmitted to a computerized form. Furthermore, data on social status (so-called Winkler-Index) were collected for each family using a structured questionnaire. The study population consisted of the families' oldest child for whom both data sets were available.  The transmission of data from the check-up booklets was time-consuming and cost-intensive due to large datasets, uncoded diagnoses as well as the necessity of trained employees for transferring often illegible handwriting. Early diagnostic tests for children enjoy a high level of acceptance among all social classes. With increasing age, attendance rate decreases gradually. Only 83 % of the population with a lower social status attend the U9 test. The documentation of diagnoses in the check-up booklets was implausible because the frequency fluctuated heavily between the different check-up time points. With only less than 2 %, the documentation of psychosocial difficulties in a child was particularly surprising  It is not possible to draw conclusions regarding the prevalence of target diseases from the frequency of documented findings in the check-up booklets. In order to make the data both comparable and evaluable, documentation must be digitalized in the future.