Abstract During the last 25 years, the close collaboration between laboratory spectrocopists and astrophysicists allowed the detection of about one hundred different molecular species in the interstellar medium, largely via their rotational emission spectra. This interaction between spectroscopy and astrophysics was initiated last century to assign the Fraunhoffer lines in the solar spectrum to atomic transitions. The first detection of molecular species (CN, CH, CH+) was made during the 1930s via their optical absorption spectra in diffuse molecular clouds. We will discuss here the recent developments in high resolution rotational spectroscopy in relation with astrochemistry and some recent interstellar detections. Some results concerning planetary and cometary atmospheres will also be presented. Finally the future projects mostly related to submillimeter and far infrared astronomy will be presented.