The present invention is related to techniques for the inspection of joints and repairs in pipelines. In this scenario, the present invention provides a method for the inspection of joints in composite pipes and of composite repairs in metal pipelines, comprising the steps of (i) emitting a series of acoustic wave pulses, at different frequencies, from a collar of acoustic transducers (4) positioned at a predetermined distance from the joint (5) or repair (1) to be inspected, (ii) recording, during a time interval subsequent to the emission, the echoes of the wave displacements up to the repair or joint in each of the transducers of the collar of acoustic transducers (4) in the form of A-Scan, and (iii) generating a planarized C-Scan image, by means of the CSM method, for each pulse emission frequency from the collar of acoustic transducers (4). The invention further provides a system for the inspection of joints in composite pipes and of composite repairs in metal pipelines associated with the method described above.