Headwater streams export CO<sub>2</sub> as lateral downstream export and vertical evasion from the stream surface. CO<sub>2</sub> in boreal headwater streams generally originates from adjacent terrestrial areas, so determining the sources and rate of CO<sub>2</sub> transport along the hillslope–riparian–stream continuum could improve estimates of CO<sub>2</sub> export via the aquatic pathway, especially by quantifying evasion at higher temporal resolutions. Continuous measurements of dissolved CO<sub>2</sub> concentrations and water table were made along the hillslope–riparian–stream continuum in the Västrabäcken sub-catchment of the Krycklan catchment, Sweden. Daily water and CO<sub>2</sub> export from the hillslope and riparian zone were estimated over one hydrological year (October 2012–September 2013) using a flow-concentration model and compared with measured lateral downstream CO<sub>2</sub> export. <br><br> Total water export over the hydrological year from the hillslope was 230 mm yr<sup>−1</sup> compared with 270 mm yr<sup>−1</sup> from the riparian zone. This corresponds well (proportional to the relative upslope contributing area) to the annual catchment runoff of 265 mm yr<sup>−1</sup>. Total CO<sub>2</sub> export from the riparian zone to the stream was 3.0 g CO<sub>2</sub>-C m<sup>−2</sup> yr<sup>−1</sup>. A hotspot for riparian CO<sub>2</sub> export was observed at 30–50 cm depth (accounting for 71 % of total riparian export). Seasonal variability was high with export peaks during the spring flood and autumn storm events. Downstream lateral CO<sub>2</sub> export (determined from stream water dissolved CO<sub>2</sub> concentrations and discharge) was 1.2 g CO<sub>2</sub>-C m<sup>−2</sup> yr<sup>−1</sup>. Subtracting downstream lateral export from riparian export (3.0 g CO<sub>2</sub>-C m<sup>−2</sup> yr<sup>−1</sup>) gives 1.8 g CO<sub>2</sub>-C m<sup>−2</sup> yr<sup>−1</sup> which can be attributed to evasion losses (accounting for 60 % of export via the aquatic pathway). The results highlight the importance of terrestrial CO<sub>2</sub> export, especially from the riparian zone, for determining catchment aquatic CO<sub>2</sub> losses and the importance of the CO<sub>2</sub> evasion component to carbon export via the aquatic conduit.