Blue Compact Dwarfs (BCD), is a subclass of dwarf galaxies which are dominated by a recent burst of star formation, responsible for their blue optical colors. Many of the BCDs are low metallicity systems, suggesting that they are genuinely young systems forming their first generation of stars and have been identified via the objective prism surveys such as the SBS. Thus they may provide an ideal local laboratory to understand the galaxy formation process in the early Universe. Using the unprecedented sensitivity of the Infrared Spectrograph (IRS) on the Spitzer Space Telescope we have observed for the first time a sample of 30 of these BCDs. Using low and high resolution mid-IR spectroscopy we examine the presence of organic molecules such as PAH and calculate their ionization field and elemental abundances. We compare our findings with similar analyses performed in normal and starbursting galaxies.