The term phonological awareness is used for a range of phonological abilities which are assumed to be the basis for effective reading, so the estimate of phonological awareness has become a key part of early identification and diagnosis of reading difficulties. Phonological awareness test do not take into account the phonological and lexical characteristics of words that have the potential to affect the phonological awareness sufficiently. This why the aim of our research was to investigate the effect of phonotactic probability (as phonological characteristic) and neighbourhood density (as lexical characteristic) on phonological awareness in the period before acquiring literacy skills and during the period of early literacy. Phonological awareness skills were assessed with three tasks: first phonem isolation, phonem segmentation and phonem blending. We used word with high phonotactic probability (PP) and neighbourhood density (NBD) as well as words with low phonotactic probability and neighbourhood density. As a limit we used value of 0,007 phonotactic probability and value of 6 for neighbourhood density. This study included 60 participants which were divided in two groups: kindergarden children (age 6;04-7;0) and school children (age 7;0-7;03). Since we wanted to examine how is the effect of phonotactic probability and neighbourhood density changing with respect to the beginning of formal education, all participants were born on the same year, to reduce the impact of development. The data was quantitatively processed in the SPSS program. We carried out Mann Whitney Test for neparametric statistics and ANOVA with repeated measures. The results show that there is statistically significant difference between the two groups of participants in phonem segmentation and phoem blending tasks. The influence of phonotactic and neighbourhood density was found only on the variables of phonem blending in the both group of participants. In addition, no interaction between the PP/NBD and the educational institution that children are attending was found on any of the variables. Further research is required, including larger number of participants of different chronological ages, using phonological awareness tasks that are suitable for their development. Future research should explore the separate influence of phonotactics and neighbourhood density on phonological awareness and further examine the influence of these as well as other phonological and lexical features on phonological awareness.