Abstract
In the last few years, the detection of Wolf-Rayet (WR) stars in Giant H II Regions (GHRs) has yielded several questions about our current understanding of massive stars evolution and hot expanding atmospheres, the age of the ionizing populations, and their impact on the physical properties of GHRs. Here, we present spectrophotometric observations of four extragalactic GHRs which show WR features in their spectra. Our goal is to reproduce simultaneously the observed WR properties and the emission line spectra with the help of current evolutionary synthesis models. Finally, we address the main advantages that the GTC will provide to our better understanding of massive star forming regions.
