We report on a study of jet shapes in inclusive jet production in pp collisions at s√=1.96   TeV using the upgraded collider detector at Fermilab in Run II (CDF II) and based on an integrated luminosity of 170   pb−1. Measurements are carried out on jets with rapidity 0.1<|Yjet|<0.7 and transverse momentum 37  GeV/c<380  GeV/c. The jets have been corrected to the hadron level. The measured jet shapes are compared to leading-order QCD parton-shower Monte Carlo predictions as implemented in the PYTHIA and HERWIG programs. PYTHIA, tuned to describe the underlying event as measured in CDF Run I, provides a better description of the measured jet shapes than does PYTHIA or HERWIG with their default parameters.