The global task of the recent decade is to search for clinical and laboratory markers accurately showing a patient’s reaction to steroid therapy and other immunosuppressive drugs. It is important the applied methods and tests to be non-invasive and simple to use. The article considers various biomarkers used to verify the type of nephrotic syndrome depending on the sensitivity to steroid therapy. Besides the common markers, which are used in clinical practice or have shown a significant result, the work highlights the molecular- genetic markers of resistance to steroid therapy, which are of special clinical importance today. Also, the article presents authors’ own results in diagnosing the steroid resistance of the primary nephrotic syndrome.