Phonological memory is a component of working memory which is crucial for phonological recoding and decoding graphemes into phonemes. It is a part of phonological processing and as such has an important role in the processing of written and spoken language, as well as reading, learning new words and understanding. It is well known that children with better developed phonological memory have better developed language skills in comparison to their peers (Waring et al., 2017). Considering the great role of phonological memory in everyday functioning, it is important to investigate how it changes in relation to age. There is an abundance of research investigating the phonological memory span in children speaking foreign languages, but there are no set norms for Croatian language. The main goal of this research was to examine the phonological memory span in typically developing children, considering the frequency of words and semantic categories that they belong to. 74 children were a part of this research. They were divided into three age groups, according to the grade of elementary school they were attending. Backwards number repetition task was used in the examination for working memory span, as well as 4 lists of 10 words which were varied regarding their frequency and semantic category (fruit, clothing items). Three problem questions occur: how word frequency influences memory span, is there a connection between working memory span and memory of high frequency words and are there differences between the three age groups. The results show that children can remember more high frequency than low frequency words. Correlation between working memory span and memory of high frequency words shows partial high correlation. Also, the difference between age groups was observed and the most significant one is the increase in memory span of children attending the third grade.