Combination of Turner syndrome (TS) and classic congenital adrenal hyperplasia (CAH) is rare. Globally, the incidence of CAH, autosomal recessive disorder caused by enzyme defect of steroidogenic pathway, is very low (1 : 10 000-16 000). 90 % of CAH cases are caused by 21-hydroxylase gene mutation (CYP21A2). Globally, the incidencie of Turner syndrome reaches 1 : 2 500. Phenotypically, females with TS may render wide spectrum of clinical features. Dominant symptoms are lowered terminal height and gonadal dysgenesia, ultimately leading to absence of puberty and infertility. Virilisation may be evident among TS women with chromosome Y 45, X/46, XY. We present a 57 year old woman suffering from both TS 45, X/46, XX and 21-hydroxylase deficiency. Based on the intersex, she was misdiagnosed as a male after the birth. Dominant signs were intrauterine growth retardation and Prader 5 virilisation of the external genitalia. Testes were not palpable. Laparoscopy at the age of 6 showed uterus and ovaries. After this examination, clitoroplasty and vaginoplasty was performed. Karyotyping revealed a 45, X/46, XX pattern. The presence of virilising features at the time of puberty however could not be explained with the diagnosis of Turner syndrome. Laboratory tests revealed elevated level of 17-hydroxyprogesterone, dehydroepiandrosterone with low cortisol concentration and elevated ACTH. With the genomic analysis CYP21A2 gene, namely IN2G (IVS 2-13 A/C>G), large deletion/conversion was detected. Glucocorticoid treatment was initiated. Due to increased plasma renin concentration, fludrocortisone therapy was also initiated. Within this therapy, patient´s state improved significantly.Key words: congenital adrenal hyperplasia - CYP21A2 - Turner syndrome - 21-hydroxylase deficiency.