The efficiency of cell destruction and extraction of intracellular contents by a high-pressure homogenizer was investigated on the Tetraselmis suecica microalgae to determine the possibility of integrating it into a biorefinery unit. Different process parameters relating to the use of a high-pressure homogenizer and biomass conditioning were tested. The parameter that has the greatest effect on cell destruction is pressure. From 40 MPa the maximum extraction yields of total proteins (80 %) and total carbohydrates (60 %) are reached and beyond 50 MPa, excessive cell destruction occurs, leading to the formation of aggregates. One single pass is sufficient to recover the maximal protein yield. Extraction in an alkaline solvent does not have a significant positive effect. Finally, it is possible to work in a wide range of biomass concentrations (from 10 g·L−1 to 100 g·L−1) and with fresh or after freeze-thaw cycles without significantly altering the yields.