Cytological examination of cerebrospinal fluid (CSF) has some specifics. In the pre-analytical phase, due to collection into a tube without fixation and hypooncotic nature with rapid cell degradation, processing is required within 2-3 hours. In the subsequent analytical phase it is necessary to take into account the quantitative limit of the sample due to regular parallel cytological processing and non-morphological methods. A regular entry step of cytological examination is the quantification of cellularity. Even oligocellular samples may exhibit severe cytological findings. In the category of inflammatory processes, the cytological diagnosis of purulent meningitis within a few hours has a fundamental influence on prognosis of the disease. Non-purulent inflammations with a broad differential diagnosis are specified not only by cytological images, but also by parallel non-morphological examinations aimed at detecting an infectious agent or autoimmune nature of inflammation. Neoplastic processes in the intermeningeal space generally require immunocytochemical verification. The minimum amount of CSF for immunocytochemical examinations is 3-5 ml. The requirement for these examinations resulting from the baseline assessment may indicate the need for another sample. If the appropriate procedures and interpretations are followed in the context of parallel non-morphological examinations, the cytological examination of MM can contribute significantly to the diagnosis of pathological conditions in CSF spaces.