Doping of semiconductors with magnetic impurities has led to formation of new class of materials, diluted magnetic semiconductors (DMSs). The most studied during last few decades are Mn-doped II-VI based DMSs. Dopant-carrier exchange interactions or so-called sp-d spin interactions are responsible for large Zeeman spin splitting of the excitonic or band states and giant magneto-optical Faraday rotation. Implementation of such a kind of magnetic doping for nanostructured materials type of nanocrystals or quantum dots gives rise to new ways of manipulating polarization of the spins of carriers and dopants. However, in this particular case there appeared problems in introducing the impurities into nanocrystals. For instance, it was revealed that the impurity atoms prefer to allocate at the surface of the nanocrystals. Up to now, the mechanism that controls dopant incorporation into nanoparticle is not fully understood. Available theoretical models are mainly applied to chemically synthesized colloidal DMS nanocrystals. No doubt, there is need in extension of such studies for the other nanocrystal synthesis techniques. In this study, we compare optical and magneto-optical properties of Mn-doped semiconductor CdS, CdTe nanocrystals prepared by different physical and chemical methods. As physical techniques we have applied ball milling or mechanical synthesis, melting powder mixtures of semiconductor and glass components, and laser ablation technique. The aqueous solution precipitation technique has served as chemical method. The Cd_1-xMn_xTe solid solution nanocrystals with Mn content x in range of (0 – 0.45) were synthesized using all the mentioned physical methods and CdS:Mn nanocrystals were prepared by the aqueous solution precipitation technique. All the samples were characterized by optical absorption, photoluminescence, and Faraday rotation spectroscopy. Contribution of magnetic ion doping was clearly visible from photoluminescence and Faraday rotation spectra. In photoluminescence spectra of Mn-doped DMS nanocrystals there appeared emission bands due to Mn²⁺ ions and their intensity increased with increasing of Mn²⁺ content. In case of CdS:Mn nanocrystals, the observed spectral dependences of the Faraday rotation confirm small contribution of sp-d exchange interaction and surface character of Mn²⁺ ion distribution.