This paper summarizes the metrological results available about saturated absorption stabilized lasers. After recalling their fundamental limitations/ we describe the present state of the art of the most important lasers : CO_ at 10.6 )jro, He-Ne at 3.39 urn ,and visible iodine stabilized sys tems. We show that there is a real need for improved performances, and that we now have all the tools necessary to fulfill this need. 1. Introduction. - During the last decade, hundreds of papers (speculative, theore tical and experimental) have been published concerning saturated absprption and optical frequency standards, and all the metrology laboratories have built and stu died their own He-Ne or CO or argon stabilized lasers. About 20 more papers pre sented at this Symposium relate the latest theoretical and experimental developments in this field. We thought it could be useful to brush a coarse picture of the pre sent state of the art in order to help the potential user in understanding what can be really expected from a saturated absorption stabilized laser. We will also try to compare the achievements with the present and future needs, hoping to stimulate some more efforts from the laser people. The performances of the various standards will be described by the usual quantities : accuracy, reproducibility and stability, defined by the Allan variance. We will specially emphasize the distinction between the reproducibility, which can be measured by comparing standards from different laboratories, and repeatability, which concerns one standard, or a series of similar standards originating from the same laboratory. This happens to be necessary since the intercomparisons of different optical standards show that the"reproducibility " estimates given by all the authors were usually too optimistic by an order of ma gnitude. After a rapid description of the more or less fundamental limitations which are common to all saturated absorption frequency stabilized lasers, we will consider the experimental realizations, with special emphasis on the I stabilized systems in the visible, the CH. stabilized systems at 3.39 Mm and the COZ systems at 10 pm. We will finally compare their performances with the present and future needs.