Objective[|]The objective of the present study was to describe the phenotypic features of Turner syndrome (TS) and to investigate the relationship between the genotype and the phenotype.[¤]Materials and Methods[|]We studied 26 female patients who were enrolled between 2006 and 2015. Physical features, clinical history, laboratory findings, and imaging test results were recorded. Chromosomal analysis was performed on peripheral blood lymphocyte cultures of the patients.[¤]Results[|]The mean age of the study population was 10.4±5.6 years (range, 1 day to 17 years). Three patients were diagnosed in the neonatal period. Although the most common phenotypic feature was short stature (92.3%), the characteristic stigmatas were usually seen in the 45, X karyotype. Among the 26 patients, monosomy 45, X was detected in 7 (26.9%) of them. Eleven percent of our patients had 46,X,i(X) (isochromosome Xq), while the rest demonstrated mosaic karyotypes [45,X/46,XY (19.2%); 45,X/46,XX (11.5%); 45,X/46,X,i(X) (11.5%); 45,X/46,XX,r(X) (7.7%); 45,X/46,X,i(Y) (3.8%); 45,X/47,XXX (3.8%); and 45,X/46,XX del(Xp) (3.8%)].[¤]Conclusion[|]TS is one of the most common sex chromosome abnormalities, but it is frequently underdiagnosed. The frequency of the monosomy 45, X karyotype in TS is less than previously thought. Therefore, patients should be evaluated by chromosome analysis in case there is clinical suspicion.[¤]