Age discrimination is becoming an exceptional problem in rapidly aging society and its consequences affect people of all age groups. This paper is intended as a comprehensive analysis of age discrimination in the labour market which may imply numerous adverse consequences for the elderly as well as in relation to young workforce. In terms of its structure, the paper is organised in seven chapters and a conclusion in addition to an introductory section. Its contents may be divided in two parts – a general, theoretical part and a special part. The theoretical part aims to define and analyse forms of the discrimination in European law and Croatian law, provide a review and analysis of anti-discriminatory regulation at the international, European and national levels, a review and comparison of situation regarding the age discrimination in the EU Member States, an analysis of the age discrimination in national legislations of individual EU Member States including the Republic of Croatia, as well as an analysis and comparison of the case-law of the Court of Justice of the European Union and case-laws of national courts concerning the age discrimination. The special part is directed at a presentation and analysis of data obtained through an empirical research conducted using an online questionnaire submitted to employees of the Osijek University and the Rijeka University. In the context of work methodology, it should be emphasised that the relevant data has been collected by application of the analysis, a synthesis and the survey methodology. Furthermore, the gathered information has been statistically analysed using descriptive and inferential statistics. Comparative methodology, as well as inductive and deductive methodologies, compilation, historical method, and proving methods were used in the course of development of the paper. The research conducted in the science and higher education system on a sample consisting of two public universities has indicated that the age discrimination exists in perceptions, but also in experience of the surveyed people. As regards the perception of the age discrimination, the research has demonstrated that the age discrimination exists in the hiring process, in the course of employment, in respect of providing equal working conditions, as well as in terms of equal opportunities for advancement. The results of the empirical research have also shown that the differences between the respondents considering their gender, level of education and particular age group are more frequent in the context of their perception than personal experience concerning the age discrimination. Furthermore, the empirical research also gave rise to a number of insights. Reluctance of victims of the age discrimination to report cases of discriminatory conduct, reluctance of the respondents, as potential victims of the age discrimination, to turn to courts as the ultimate instance for protection of their rights and an exceptional low level of awareness of existence of the Anti-Discrimination Act and its contents. Prevention of discrimination is a complex work requiring engaging and coordinated action of all entities in the labour market. Undoubtedly, steps towards achievement of that objective comprise mobilising the public for the combat against prejudice and stereotypes, raising awareness of the public and institutions concerning the discrimination as impermissible conduct, recognition of outcomes of informal and non-formal learning, changes in the education system, changes in the field of active labour market policies, systematic education on legislation combating the discrimination, the European law, case-law of the European courts, and the need for its application, social dialogue and social negotiation, conclusion of collective bargaining agreements, and application of the diversity management concept.