A novel range of sulphonamido porphyrins based on meso-tetraphenylporphyrin has been synthesized and assessed for Langmuir-Blodgett (LB) deposition. Those substituted with long hydrocarbon chains have been shown to form stable Langmuir films. On acidic subphases the molecules become protonated as the film is compressed. Molecular areas suggest that the porphyrin rings are packed in a tilted arrangement on the water surface. When these material are transferred onto solid substrates a preferred molecular orientation perpendicular to the dipping direction is observed.