The aim of this research was to examine the morphological characteristics of acorn in order to the determine differences between three species. In total, sixteen primary and two secondary parameters were measured and statistically processed. The present study included a total number of 400 acorns from three oak species (pedunculate, sessile and Turkey oak). Acorns were collected from four different sites. Pedunculate oak acorns were collected in Novi Sad and Bačko Petrovo Selo, while sessile and Turkey oak acorns were collected from two different sites at Fruska gora Mt. Following statistical methods were used in this paper: t- test, ANOVA, principal component analysis and analysis of correlation. The results of t-test pointed out statistically significant differences between all characters within two different sections. Statistically significant differences in the examined characteristics were also found between the acorns of two pedunculate oak populations collected at two different sites. The analysis of variance showed statistically significant differences between all investigated characters for all three oak species. The results of PCA pointed out that acorn mass, stalk length, nut length, nut diameter and nut out of cupule are the characteristics can be used to differentiate three mentioned oak species. The same patterns of correlations were established for all three examined oak species. The present study is discussing the significance of the results related to assessment of morphological characteristics of acorns for application in selection and breeding programmes.