Cerebrospinal fluid (CSF) reflects the pathological processes in neural tissues, therefore, by analyzing it, pathologies can be detected. In our study, we applied infrared (IR) spectroscopy for the analysis of dried infectious and normal CSF films of 30 patients. The presence of glucose, bicarbonates, amino acids and lactate was established from the attenuated total reflectance (ATR) IR spectra. The differences between infectious and normal CSF samples are related to lactate and amino acids and allow one to distinguish these two sample groups. The applied method allows one to analyze a small sample amount that is an advantage compared to the routine clinical evaluation of the CSF where significantly larger amounts of the fluid are required.