Morality has been studied by various branches of psychology, but the most impactful theory on that field is L. Kohlberg's theory of moral development. Continuing the work of J. Piaget, Kohlberg assumes that the moral development follows an invariant set of three stages, with two levels on each stage: preconventional, conventional and postconventional. One of the central concepts of this theory is the concept of moral reasoning, which can be defined as a process of mental reasoning that leads to moral decision. However, this theory has received some criticism, since the connection between behaviour and moral reasoning was questionable. On the other hand, the concept of moral decision-making should eliminate that problem, because it sets an individual in an egocentric perspective, instead of being just a passive observer. That kind of approach should lead to higher levels of relating to the situation and thus the engagement of certain emotions. Therefore, moral decision-making can be understood as a cognitive and an affective load for the individual, which should cause certain changes in the physiological plane. Previous research has shown the that changes in the cardiovascular activity occurs during mental load, but also when experiencing certain emotions. The goal of this study was to examine if the changes in the cardiovascular activity really occur during the course of moral decision-making, through five different scenarios, that were divided into periods of rest, periods of reading the moral dilemmas and periods of decision-making, and to examine the connection between the morality of the respondents and cardiovascular activity. Statistical analysis showed that the values of time domain parameters (mean (MRR) and standard deviation (SdRR) of RR intervals and the square root of the mean squared differences of successive RR intervals (RMSSD)) were red1ucet in the periods of reading and decision-making in comparison to the period of rest. Only MRR was reduced in all 5 scenarios, while the values of SdRR and RMSSD were reduced in only one of the scenarios for the period of reading or decision-making in comparison to the period of rest. Analysis also showed that the values of the frequency domain parameters (normalised units of low (nuLF) and high (nog) frequencies and their ratio (LF/HF) do not differ between different situations and scenarios. Finally, it turned out that there are no connections between the morality of respondents, operacionalised by the individuals result in the Test of moral decision-making (TMO) and different parameters of cardiovascular activity.