Many various methods are known today in order to prepare semiconductor compounds nanocrystals in liquid media [1-3]. Most of them use different surfactants as stabilizers for nanocrystals, thus determining their various chemical and physical properties, such as solubility in various media, dimensional, aggregative and kinetic stability, as well as stability against photocorrosion; they can even change the position of the optical absorption edge or can activate/suppress luminescence. One of disadvantages of the known synthesis methods is their requiring of inert, pure medium, dangerous reagents, complex equipment and/or complex procedures of storing and handling reagents, a very strict control of the synthesis conditions. The cleaning and neutralizing of toxic waste are also to be carried out many times. As an alternative to these methods, we are proposing a simple method of synthesis in aqueous colloidal solutions of PbS or PbSe nanocrystals using gelatine as a stabilizer. The synthesis is carried out in an aqueous gelatine solution by the reaction between sulfur/selenium and lead precursors, the reaction temperature and reactives concentration serving as control parameters. As a result, in a couple of minutes, at temperatures close to the room temperature, water soluble PbS or PbSe nanocrystals can be obtained without using inert media, toxic reagents or expensive compounds. Desirable changes in the size of nanocrystals in a broad range (2-20nm) can be achieved by modifying the acidity of the solution, reagents concentrations, S or Se to Pb molecular ratio or the synthesis temperature. The changes in particle sizes was proved by the changes in the position of the maxima of excitonic luminescence spectra in the range 800-2000 nm. The dependence of the final dimensions of nanocrystals on the concentration of gelatine in the aqueous solution of gelatine with lead nitrate was found to be the following: when the gelatine concentration was arised up to 12 – 20%, then there was noticed a slight displacement of the maximum position of the band of excitonic luminescence towards the shorter wave length, and a decrease of the average diameter of nanocrystals. When the gelatine concentration was set in the range 0.5 - 12%, then the maximum of the excitonic luminescence remained practically unchanged, and the final diameter of nanocrystals remained unchanged. With the raise of temperature from 20 to 90°C, the maximum of the photoluminescence spectrum was found to become monotonously displaced from the lowest value of 800nm to the highest of 1500nm, which means the increase of the crystals diameter. The growth of the ratio of S:Pb in the mixture for the synthesis from 1:4 up to 4:1 leads, first, to the increasing of the luminescence wavelength (crystal diameter), reaching the max. at the ratio 2:1, after which is starts to decrease back. The experimental data showed that the decrease of the pH of the solution from 13 to 4 did not result in a significant change in the dimensions of the produced nanocrystals, but there was a sharp increase of the crystals dimensions when pH was made lower than 4. The method presented here has some advantages over many other known synthesis methods, namely: it is simple and fast; it makes it easy to controll the final size of nanocrystals; there is no need in complex and expensive equipment; it use non-toxic, non-expensive and not easy-degradable reagents; it produces no harmful residues and, last, but not least, the obtained nanocrystals are soluble in polar environments, such as water.