The present invention relates to an inkjet ink composition comprising a liquid vehicle and at least one polymer modified pigment. In one embodiment, the polymer modified pigment comprises the combination product of a pigment, a polymer, and a base, wherein the polymer is a styrene-maleic anhydride polymer or an alternating copolymer comprising at least one segment having the formula --[HB-A].sub.x-. In a second embodiment, the polymer modified pigment comprises a pigment and a polymer, wherein the polymer is a styrene-maleic acid polymer or salt thereof or an alternating copolymer comprising at least one segment having the formula --[HB-A'].sub.x-. Methods of preparing the inkjet ink compositions are also disclosed.