Objectives: The main objective of this research is to determine the most common indications for lumbar puncture in the Day-care Hospital in Department of Neurology, University Hospital Split in a one-year period. The research covers the period from January 1, 2022 to December 31, 2022. Also, we want to see the basic characteristics (age and gender) of patients for whom lumbar puncture was indicated in the specified period. Materials and methods: A retrospective observational study was conducted. Data were collected on all patients registered in the protocol book of the Day-care Hospital in Department of Neurology, University Hospital Split, who underwent LP. Data on age, gender and diagnoses were statistically processed to obtain information on the most common indications for lumbar puncture, as well as information on the age and gender of patients for whom lumbar puncture was indicated. Results: The research included 69 patients who, in the period from January 1, 2022 to December 31, 2022, were indicated for a lumbar puncture as a part of the diagnostic treatment in the Day-care Hospital in Department of Neurology, University Hospital Split. Among these patients, 69.6% or 48 patients are women, while 30.4% or 21 patients are men. Lumbar puncture was indicated for 35 different diagnoses, which means that the diagnoses are mostly not repeated. The largest number of patients, 11 of them, were referred for lumbar puncture due to suspected diagnoses of G37 (Demyelinating disease of the central nervous system, unspecified) and G37.9 (Other demyelinating diseases of the central nervous system) according to the ICD-10 classification. They are followed by the diagnosis G35 (Multiple sclerosis) with a total of 10 patients. The largest number of patients for whom lumbar puncture was indicated is in the age group of 41-50 years. The median age of all patients was 44 years (IQR=31.00-51.00). Conclusions: Multiple sclerosis is not the most common indication for lumbar puncture in the Day-care Hospital in Department of Neurology, University Hospital Split in one-year period. Dementia was not an indication for lumbar puncture in a one-year period. The number of women with demyelinating diseases of the CNS is greater than the number of men with demyelinating diseases of the CNS.