We will review theoretical, experimental and observational work on the new form of carbon known as fullerenes and its hydrogenated forms (fulleranes). This type of molecules can be responsible for diffuse interstellar bands, for the UV ``bump", a remarkable feature of the extinction curve observed in many lines of sight of our Galaxy and other galaxies, and for the anomalous microwave emission detected in regions of star formation, in molecular clouds and HII regions. The recent detections of the fullerenes C_{60} and C_{70} in planetary nebulae of our Galaxy and in the Magellanic clouds provide further support to the hypothesis that these fullerenes are common in the interstellar medium. I will also review advances in the identification of polycyclic aromatic hydrocarbons (PAHs) which are also potential agents of the previous phenomena.