This review focuses on the “green translocases”, representatives of the highly conserved Alb3/Oxa1/YidC protein family and their role in the formation of photosynthetic membranes. Members of the green translocases are designated Slr1471 in Synechocystis PCC 6803, Alb3.1 and Alb3.2 in Chlamydomonas reinhardtii and Alb3 and Alb4 in Arabidopsis thaliana. Alb3/YidC-like proteins are polytopic membrane proteins and comprise five transmembrane regions. Furthermore, members of chloroplasts are known to contain a pronounced C-terminal sequence for which an α-helical superhelix (“coiled-coil”) domain was predicted. Interaction of this domain with nascent polypeptides may assist in the insertion of the protein in a cotransational manner. While the bacterial homologue, Slr1471 seems to still localize to the plasma membrane, representatives of chloroplasts localize to the thylakoid membranes. During the evolution of the photosynthetic membranes, the thylakoids, adaptations of the  protein  transport  systems  were  essential  for  inserting  proteins  into  this  new  compartment.  Analysis performed on loss-of-function mutants or knock-down mutants of Alb3/YidC-like proteins demonstrate that these factors function in the integration of membrane proteins into thylakoid membranes and assist in the assembly of high molecular weight complexes. Furthermore, a modest decrease in some of the Alb isoforms had already a strong effect on the viability of the mutants indicating that the green translocases are not exclusively involved in the biogenesis of thylakoid membranes.