An ink composition is provided that includes (A) an N-vinyllactam, (B) a (meth)acrylic acid ester and/or amide having at least 3 alkylene oxide groups per molecule, and (C) a polymerization initiator, the content of the N-vinyllactam (A) being at least 10 wt % of the ink total weight. There is also provided an inkjet recording method that includes (a1) a step of discharging the ink composition onto a recording medium and (b1) a step of curing the ink composition by irradiating the discharged ink composition with actinic radiation. A printed material recorded by the inkjet recording method is also provided. Furthermore, a process for producing a lithographic printing plate is provided that includes (a2) a step of discharging the ink composition onto a hydrophilic support and (b2) a step of curing the ink composition by irradiating the discharged ink composition with actinic radiation so as to form a hydrophobic image on the hydrophilic support by curing the ink composition.