Recurrent Forbush decreases and recurrent geomagnetic disturbances have been attributed to the solar M regions, which are sources of high‐velocity solar plasma streams. A study of recurrent Forbush decreases for the period 1966‐1975 has been made to examine any possible relationship of M regions with solar active regions. It is shown that at the onset of the recurrent Forbush decrease at the earth there is a high probability of encountering a class of active regions at the central meridian of the sun which give rise to flares of importance ≥2B/3N. These active regions are found to be long lasting and to have large areas as well as high Hα intensities. Other active regions, producing flares of lower importance, are distributed randomly on the sun with respect to the onset of a recurrent Forbush decrease. By using the quasi‐radial hypervelocity approximation the base of the leading edge of the high‐velocity stream at the onset of a recurrent Forbush decrease at the earth is traced to the solar longitude about 40° west of the central meridian. From these results it is deduced that M regions are located preferentially to the west of long‐lasting magnetically complex active regions. Earlier studies of the identification of the M regions on the sun have been reexamined and shown to conform to this positional relationship. A possible mechanism of the development of an M region to the west of the long‐lasting magnetically complex active region is also discussed.