In this paper we report on the results of examining selected features of Polish vowels in adult directed (ADS) and infant directed (IDS) speech, using Carstens AG501 electromagnetic articulograph (EMA). According to phonetic-acoustic research results, the characteristics of Polish IDS include e.g. higher durational variability, wider range of f0 changes, and higher F1/F2 ratio than ADS. Here, we provide new insights into the two speaking styles by discussing the specificity of the articulatory movements during speech production. The present EMA dataset is the first collection for Polish enabling such a comparison. The session scenario assumed recording of short utterances in two experimental conditions (ADS and IDS). The dataset comprises movement trajectories for 14 sensors (and referential sensors) in the x-axis (front-back), y-axis (left-right), z-axis (top-down). We also recorded audio signal and video image of all sessions. Thus, the dataset supports a combined description of the EMA results and phonetic-acoustic features in ADS and IDS. The statistically significant differences between ADS and IDS relate to e.g. the lip corner and lower lip sensor positions along the x-axis, as well as the shape of the tongue mass expressed by the differences in the tongue back position along the x-axis.