The present review summarizes current applications of the NMR phenomenon in paramagnetic systems for studying structure and intramolecular dynamics of multielectron molecular systems. The potential of spin labels for molecular identification was demonstrated in the example of structural biology issues. Discussion of molecular structure of specific organic heteroatomic compounds and their complexes is preceded by the section, where peculiarities of the NMR phenomenon in paramagnetic systems are considered. In opinion of the authors of the review, such consideration is needed for researchers who are not experts in the NMR theory. The separate section of the review is devoted to a method for investigation of structure and dynamics of complex molecular systems. This method is based on application of the NMR spectra transformed by complexes, first of all, paramagnetic ones (spin labels).