We present infrared and optical spectroscopic data for 11 H II regions and one Supernova Remnant in the Large and Small Magellanic Cloud. The infrared data have been obtained with the Short Wavelength Spectrometer and Long Wavelength Spectrometer on board the Infrared Space Observatory as part of a Guaranteed Time Program on H II regions in Local Group Galaxies. Aim of this project is to give a new and improved analysis of the physical structure of the sample H II regions by combining as much spectral data as possible. A detailed account is given here of the reduction process, and the quality and reliability of the presented fluxes are discussed