Self-reinforced fibre composites are solely based on the bonding of matrix and fibre identical thermoplastics and hence do not rely on fibre reinforcements of a foreign material. The self-reinforcement can be transferred to hot-compacted fibre composites by means of stretched textile semifinished products. The two processing conditions temperature and process time, in particular, have a significant influence on the macromolecular orientation and the degree of compaction. Within the framework of these investigations, the effectiveness of the degrees of compaction achieved this way are characterised and discussed on the basis of both non-destructive ultrasonic testing of selected fibre composites and additional quasi-statistically determined tensile properties.