  We discuss our high precision radial velocity results of a sample of 90 M
dwarfs observed with the Hobby-Eberly Telescope and the Harlan J. Smith 2.7 m
Telescope at McDonald Observatory, as well as the ESO VLT and the Keck I
telescopes, within the context of the overall frequency of Jupiter-mass
planetary companions to main sequence stars. None of the stars in our sample
show variability indicative of a giant planet in a short period orbit, with a <
1 AU. We estimate an upper limit of the frequency f of close-in Jovian planets
around M dwarfs as < 1.27% (at the 1 sigma confidence level). Furthermore, we
determine the efficiency of our survey to have noticed planets in circular
orbits as 98% for companions with m sin i > 3.8 M_Jup and a < 0.7 AU. For
eccentric orbits (e=0.6) the survey completeness is 95% for all planets with m
sin i > 3.5 M_Jup and a < 0.7 AU. Our results point toward a generally lower
frequency of close-in Jovian planets for M dwarfs as compared to FGK-type
stars. This is an important piece of information for our understanding of the
process of planet formation as a function of stellar mass.
