This paper deals with the analysis of the phenomenon of gas pressure drop across distributors with high free area ratio as used in multistage fluidized-bed vessels without standpipes. The phenonemon has been studied for selected types of plate distributors, viz. orifice distributors and slot distributors. On the basis of experimental studies, performed in the range phi = 0.1-0.4, information has been obtained about the character and magnitude of the effect of the fluidization conditions and the constructional features of the distributor upon the pressure drop in question. The similarity factors of the phenomenon have been analyzed for both distributor types. Equations describing the gas pressure drop through the distributor as a function of its constructional parameters have been derived and verified experimentally. It has been shown that one such equation [Eq. (18) in the text] when elaborated for orifice distributors with high free area ratio and taking the shape of the orifice’s profile into account may be used for the calculation of the pressure drop through conventional distributors. Analogies between the analytical approach to various phenomena connected with the distribution of gas in fluidized-bed apparatus are presented.