Abstract: Bathymetry and the bottom sediments of Lake Eymir, remnant of and old meandering river situated 15kilometres south of Ankara, have been studied. The lake bottom is pan shaped and neary flat The deepest part occurs atthe middle, where 5.5 m of depth has been recorded; there is a gradual shallowing towards both ends. Bottom muds arevertically structureless down to a depth of 20 cm, possibly due to bioturbation activity. The sediments are filling thelake as suspension loads particularly from both ends. At these shallow SW and NE ends silt is dominant. At the lowerends of alluvial fans where they reach lake banks, sandy gravel, sand and sandy silt also occur as nanrow zones. The sediments in the broad central depression of the lake have a very fine silt and clay grain size. Sorting is "poor" to "verypoor", skewness and kurtosis values show local variations within the lake. Mineralogy stongly reflects the characteristics of the hinterland teiranes. Organic content of the bottom surface sediments increases towards the center of the lake.