Objectives: This research aimed to do two things: the first was to determine whether or not the infusion of crystalloid solutions within the first 24 hours followed by the infusion of colloid solutions within the next 24 hours decreases mortality rate in burn patients; the second, to see whether or not the outcome of the treatment was in any way connected to gender, age, percentage of burnt area, complications caused by the burns and risk factors. Subjects and methods: This retrospective research included the total of 49 burn patients who were treated in the ICU at the University Hospital of Split (Croatia) between the 1st of January 2015 and the 31st of December 2020. Patients were differentiated according to their age, gender, TBSA (%), health complications, type and quantity of fluids administered within the first 48 hours, as well as information on diuresis in the first two days. Specific formulae were used to determine the quantity of fluids that should have been administered and urinated in the first two days so as to compare them to the outcome of the treatment. Results: The research has shown that the patient's age and the percentage of burnt surface of the body influence greatly the outcome of the treatment. The chances of a lethal outcome are 5 times higher in each age group (the span of 10 years was used to determine age groups). The rise of TBSA by only 10% makes the chances of a lethal outcome 2.7 times higher in each age group. A formula was used to calculate the percentage of administered crystalloids within the first 8 hours and colloids in the second day in relation to the quantity necessary to survive. The research has partially proven that the patient's chances of survival grow depending on the percentage of administered fluids. The impact of gender on the outcome of the treatment can be explained by the female domination in older age groups. The presence of a larger number of complications and risk factors both increase the probability of a lethal outcome. Conclusions: This research has shown that the age and the percentage of the burnt surface of the body are connected to the outcome of the treatment. The positive influence of resuscitated fluids within the first 48 hours has been partially confirmed. The research has also shown that a larger number of health complications and risk factors increase the chances of a lethal outcome.