Routine laboratory data are discussed by time series analysis in reversed clinicopathological conferences (R-CPC) at Shinshu University School of Medicine. We can identify fine changes in the laboratory data and the importance of negative data (without any changes) using time series analysis. Routine laboratory tests can be performed repeatedly and relatively cheaply, and time series analysis can be performed. The examination process of routine laboratory data in the R-CPC is almost the same as the process of taking physical findings. Firstly, general findings are checked and then the state of each organ is examined. Although routine laboratory data are cheap, we can obtain much more information about a patient's state than from physical examinations. In this R-CPC, several specialists in the various fields of laboratory medicine discussed the routine laboratory data of a patient, and we tried to understand the detailed state of the patient. R-CPC is an educational method to examine laboratory data and we, reconfirmed the usefulness of R-CPC to elucidate the clinical state of the patient.