Volumetric modulated arc therapy (VMAT) irradiation plans are a potentially improved version to the now widespread intensity-modulated radiotherapy (IMRT) irradiation techniques, which in turn are gradually replacing traditional conformal breast irradiation techniques. The aim of this study was to dosimetrically compare VMAT and IMRT radiotherapy plans for lymph node positive breast cancer irradiations. Patients over the age of 18, with lymph node positivity and stage II or stage III classification (according to the AJCC/ UICC), were selected for our study. Several IMRT and VMAT plans were prepared and compared for all the investigated patients. According to our results the VMAT technique leads to equal results in terms of the target area, while providing comparable outcomes for the organs at risk (OAR). We also noted that the treatment times and monitor units are considerably lower for VMAT plans.