It is shown that a generalized Ito system of four coupled nonlinear evolution equations passes the Painleve test for integrability in five distinct cases, two of which were introduced recently by Tam et al. [H. W. Tam, X. B. Hu, D. L. Wang: J. Phys. Sec. Jpn. 68 (1999) 369]. A conjecture is formulated on integrability of a vector generalization of the Ito system.