The centrifugal film reactor is an original gas-liquid contactor which presents good gas-liquid mass transfer characteristics. The aim of this study is the determination of the gas and liquid side mass transfer coefficients k(G)A and k(L)A as well as that of the gas-liquid interfacial area A in such a reactor. The following techniques were used : k(G)A is determined by using the absorption of dilute SO2 in a sodium hydroxide solution. k(L)A is determined by 4 different techniques : the physical absorption of SO2 in a sulphuric acid solution, the oxidation of sulphite ions (Danckwerts plot technique), the absorption of CO2 in a carbonate/bicarbonate buffer, the absorption of oxygen in a hydrazine solution. A is determined by the oxidation of sulphite ions (Danckwerts plot technique). The investigated parameters k(G)A, k(L)A and A depend mainly on the rotational speed N and on the back pressure Delta P which can be combined in an Euler number, and on the coalescence properties of the liquid. The following orders of magnitude are obtained : k(L) : 5-40 x 10(-4) m s(-1) k(G) : 2.5-25 x 10(-3) m s(-1) a : 30-200 m(-1) (reference volume : the reactor).