According to the present invention a method and an exhaust treatment system, are provided for treatment of an exhaust stream, which results from a combustion in a combustion engine and comprises nitrogen oxides NOX. The method comprises a first oxidation of compounds comprising one or more of nitrogen, carbon and hydrogen in the exhaust stream. Further, a control of a first supply of a first additive in the exhaust stream is carried out. This control is carried out with the objective of preventing an accumulation of soot exceeding a soot threshold value Sth in a catalytic filter arranged in the exhaust treatment system. This soot threshold, value Sth depends at least on operating conditions for the combustion engine, which impact a level of a flow for the exhaust stream. A first reduction of nitrogen oxides N0X in the exhaust stream is carried, out with the use of reduction characteristics of an at least partly catalytic coating comprised in the catalytic filter and with the use of the supplied first additive. Additionally, soot particles in the exhaust stream are caught and oxidised, A control of a second supply of a second additive in the exhaust stream is carried out, following which a second reduction of nitrogen oxides NOX in the exhaust stream is carried out with the use of the first and/or the second additive in. a reduction, catalyst device.