Complete data set of earthquakes in Turkey and the adjacent areas has been used in order to compute the omega values in 24 seismic regions of Turkey. The parameter is obtained through Gumbel's third asymptotic distribution of extreme values and is well known as upper bound magnitude. This is an interpretation that no earthquake magnitude greater than omega can occur in a region. The results also estimate the most probable magnitude for a time period of 100 years. The estimates of omega exceed the value of 7.00 in 20 of the 24 seismic regions. An effort is also made to find a relation between the magnitude and the length of a fault in the complicated tectonics of Turkey and the surrounding area. Earthquake hazard revealed as tables and maps are also considered for Turkey and the surrounding area.