Uncharged water-soluble porphyrins were prepared by reaction between tetrakis(p-hydroxyphenyl)porphyrin and chlorinated poly(ethylene glycol) methyl ethers of differe molecular weights. Water-solubility was achieved by binding four poly(ethylene glycol) branches to a porphyrin core to give star polymers with molecular weights in the range 2000-21000 Da. Structural characterization of these star polymers was performed by means of gel permeation chromatography, NMR spectroscopy, and MALDI-TOF analysis.