Numerous studies show that children, due to insufficient life experience and, consequently, insufficiently developed critical thinking towards the consumed media content, are extremely susceptible to manipulation in the media and are therefore considered as a vulnerable social group. Assuming that children spend most of their free time watching cartoons on television, for the purpose of the thesis, a content analysis of cartoons on Croatian television channels was conducted to investigate whether stealth marketing or product placement appears in broadcast cartoons and what their level of presence is. Stealth marketing integrates the ad within the media content and the audience rarely perceives it as an ad. Also, the thesis was based on the conceptual definition of terms from marketing communication, especially stealth marketing, and issues that manifest themselves due to its inconsistent conceptual definition within the Croatian law, professional literature, and marketing practice in Croatia. Within the thesis, the types of stealth marketing and product placement are classified and the historical, legal, and ethical aspect of this type of advertising is reviewed. The analysis shows that stealth marketing can be found in cartoons broadcast on Croatian television channels under national concession, and through an analytical approach the need for systematic monitoring of media content targeted towards children is identified, same as the necessary adjustment of legislation, professional marketing literature and market practice in Croatia.