Misconceptions are widely present among the students of all ages. The aim of this investigation was to determine the presence of misconceptions in understanding physical properties of water and to identify the most common ones. Quantitative analysis of data from the diagnostic conceptual test was performed on a sample of 243 first and third grade students from three elementary schools in Sombor, Serbia. It was shown that the impact of gender and school affiliation were not proven to be statistically significant factors in test achievements, while the children’s age significantly affects test results, as expected. Synthetic and scientifically correct answers were more frequent among the third grade students, while spontaneous answers were more common among the first graders. Nevertheless, a significant proportion of spontaneous answers implies that misconceptions about physical properties of water are almost identical and deep-rooted among students of both ages. Identifying children’s misconceptions provides a basis for development of accurate conceptual understanding.