The topic of this master´s thesis is gender identity as a legal basis for the prohibition of any form of discrimination in the areas of work and employment. The definition of gender identity is given in various professional literature, within the fields of both, sociology and psychology. The internal legal regulations of the Republic of Croatia that contain provisions on discrimination are: Law on Suppression of Discrimination, Law on Labor, Law on Gender Equality, Law on Life Partnerships of Persons of the Same Sex and Law on Same-Sex Unions. The most important international ones are: the Charter of the United Nations, the Universal Declaration of Human Rights, the International Covenant on Civil and Political Rights and many others. After defining gender identity, this paper also explains the factors and age that influence the formation of gender identity and the difference between sex and gender. In addition to the above, special attention is focused on the legal and social position of transgender people in the Republic of Croatia and the discrimination they are subject to because of their gender. Through the prism of gender, the problem of general discrimination of all women on the labor market, the inequality of women and men in working relationships, and the mechanisms of protection of the rights of all workers on the labor market were addressed. Numerous scientific books, laws, professional magazines and various internet sources were used as literature for writing this paper.