Malignant hypertension (MH) is a state which can rapidly progress to multi-organ failure. It can develop in the course of both primary and secondary type of hypertension. In our study, we present a case of a 36-year-old man diagnosed with renal failure and MH complicated with retinopathy. As the secondary nature of the condition was suspected extensive diagnostics has been conducted. In spite of excluding plenty of pathologies, the underlying cause remained unknown. Eventually, the renal biopsy has been performed, leading to a diagnosis of IgA nephropathy. However, symptoms and course of the disease has not been typical. Nevertheless, IgA nephropathy should be considered as a possible cause of secondary hypertension as well as malignant hypertension. The diagnosis is not easy and a crucial role is played by renal biopsy.