An exhaust gas purification system for diesel engines includes at least one oxidation catalytic converter, a reducing agent injection device and a reduction catalytic converter disposed together in a housing having a first lateral chamber close to a first end side and a second lateral chamber close to a second end side. The reduction catalytic converter is disposed in the first lateral chamber, the oxidation catalytic converter is disposed in an outer annular space of the second lateral chamber and the reducing agent injection device is oriented toward an inner channel of the outer annular space of the second lateral chamber. A flow path for the exhaust gas from at least one exhaust gas inlet toward at least one exhaust gas outlet is provided through the oxidation catalytic converter, the reducing agent injection device and the reduction catalytic converter.