We studied the population relationships of Krüper's Nuthatch (Sitta krueperi) by capturing 82 individuals using mist nets in six different areas in Turkey during the breeding season, from March to June 2005–2008. Forty-one different morphometric characters were measured. Morphometric characters measured (x ¯ ± SD) were: body mass  =  13.11 ± 0.88 g, wing length  =  74.79 ± 2.35 mm, bill length  =  17.65 ± 0.76 mm, and tarsus length  =  19.10 ± 0.93 mm, respectively. A stepwise discriminant analysis of four populations retained seven statistically significant measurements: body mass, wing length, length of P 8, alula, bill height, back nail, and left nail. These analyses allowed discrimination among populations. The population in the Aladağlar Mountains differed from others even though it overlapped with the population in the Lütfi Büyük Yıldırım Research Forest, and marginally with the population at Kartalkaya Mountain. Cross validation for the other three populations confirmed large overlap in morphometric characteristics although the population at the Lütfi Büyük Yıldırım Research Forest seemed to be intermediate between populations at Aladağlar Mountains and in the Kazdağları Mountain-Kartalkaya Mountain complex.