With the outbreak of the global pandemic during the year 2020, induced by the COVID-19 virus, healthcare systems around the world, along with the one in the Republic of Croatia became extremely overloaded. The rapid spread of the virus contributed to sudden changes and expanded workload, increasing the risk of infection with a new virus and thus increasing the stressfulness of working conditions. Such a situation puts healthcare professionals into a working context that is marked by extreme physical and psychical efforts and threats. The aim of this study was to examine some aspects of general and work well-being among healthcare professionals in the Republic of Croatia by applying longitudinal study where the values of the examined variables were measured during the two pandemic waves (in May of 2020 and throughout November and December of 2020). In this study, the general well-being was measured with self-assessment levels of depression, anxiety, stress and mental health, while work well-being was measured with levels of job satisfaction and burnout at work (which includes disengagement and exhaustion). Considering the epidemiological situation, the study was conducted via an online version of the questionnaire. A total of 92 health professionals from 15 different counties of the Republic of Croatia participated in this study. 89.1% (N=82) of participants were female and 10.8% (N=10) of participants were male. Out of 92 participants, 88 (95.65%) of them were nurses/technicians, and four of them were doctors (4.35%). The results confirmed the hypothesis that the levels of depression, anxiety and stress increased in the second measurement compared to the first. Nevertheless, although there has been growth in mental health levels, the difference was not statistically significant. Moreover, the increase in exhaustion levels proved to be the only statistically significant difference between examined variables related to work well-being. The level of disengagement, contrary to expectations, did not increase statistically significantly nor did job satisfaction decrease statistically significantly. Also, the results have shown that there is, indeed a link between general and work well-being. Specifically, elevated levels of depression, anxiety and stress as well as lower levels of mental health are positively associated with higher levels of disengagement and exhaustion, and they are also in a negative correlation with job satisfaction. Furthermore, there was a significant interrelation of the constructs of work and general well-being between two measurements. Some of the variables of working well-being from the first measurement were statistically significantly associated with the variables of general well-being from the second measurement.