The main objective of the present paper is to analyze the effects of phase-lag on thick circular plate with heat sources in modified couple stress thermoelastic medium. The mathematical formulation is prepared for three-phase-lag heat conduction model subjected to prescribed normal heat flux along with stress free boundary. Laplace and Hankel transforms are used to deal the problem. The displacements, stresses and temperature change are obtained in the transformed domain. Numerical inversion technique has been used to obtain the solutions in the physical domain. The results obtained numerically for these quantities are presented graphically. Some particular cases are also discussed in the present problem.