We investigate the phenomenon of oscillatory growth of fungal hyphal tips. Growing mycelium was recorded with photo-enhanced microscopy at regular time intervals (5 and 15 min). It was shown that the process of hyphal tips elongation is not steady and includes alternating periods of fast and slow growth. The analysis of growth rhythms allowed to determine the values of growth periods and their characteristics. These periods are in fact chaotic and don't depend on nutrient medium composition and fungi growth rates, probably having endogenous cause.