The interaction of sulfonated tetraphenylporphins H2 TPPS4(HCl)2 and in CuTPPS4 with poly-N-vinylpyrrolidone (PVP) is studied using small-angle neutron scattering, dynamic light scattering, visible spectrophotometry, and viscometry. It is shown that porphyrin molecules form complexes with PVP, thus charging the polymeric chain.