Effective amplification of diode-pumped picosecond laser oscillators employing grazingincidence side-pumped slab modules has been reviewed. Numerical models, useful for the design and the investigation of the amplifier characteristics, both in terms of energy extraction and pulse dynamics, have been illustrated. Some particularly representative examples of such amplification techniques, under various operating regimes, have been reported and discussed, comparing their results with the numerical model and putting them in perspective against other state of the art amplification schemes. The most distinctive features of grazing-incidence amplifiers can be summarised as follows: · extremely high gain that allows considerable setup simplification; · strong gain shaping allowing beam quality preservation along the fast axis of the diode array, notwithstanding the strong thermal lensing in that direction;