Abstract This publication investigates the adhesion between an injection molded component and a self-reinforced composite (SRC) produced in a combined compaction and back-injection process to produce back-injected self-reinforced composites. To study the influence of the process, the parameters barrel temperature, time of injection, and tool temperature were varied. In addition, samples were taken at different positions along the flow path. In light of the orthotropic material behavior of SRCs, investigations were conducted to see whether different loading cases lead to different mechanical behavior. Shear-off and pull-off tests revealed a different strength as a function of the loading type. In the shear-off tests, a mean strength of 11.37 MPa was recorded over the entire test series, while the measured mean strength in the pull-off tests is considerably lower, 4.04 MPa. The type of failure is determined with the aid of SEM images, and the influence of the microstructure of the thermoplastic fibre materials on the adhesion is set out. It is shown that, as of a sufficiently high level of adhesion, failure occurs within the fibres.