The present invention relates to a downhole stimulation system for stimulating production. The system has first and second inflatable packers (6) for isolating a production zone (10), the packers being inflated through aperture (15), a sliding sleeve valve (17) arranged between the two packers, the sleeve having an opening (19) to provide fluid communication between the inside of the well tubular and the production zone. In operation the inflatable device is set downstream of the inflation aperture of the lower packer, the well is pressurized to move the tool downstream to open the sliding sleeve valve, whereafter fracturing fluid with proppants having a size which is smaller than that of the sliding sleeve opening (19) and larger than the packer inflation aperture (15), is pumped downhole using a displacement means such as a piston element.