In this paper , we present the effects of dark energy perturbation on the formation and abundance of cosmic voids . We consider dark energy to be a fluid with a negative pressure characterised by a constant equation of state w and speed of sound c _ { s } ^ { 2 } . By solving fluid equations for two components , namely , dark matter and dark energy fluids , we quantify the effects of dark energy perturbation on the sizes of top-hat voids . We also explore the effects on the size distribution of voids based on the excursion set theory . We confirm that dark energy perturbation negligibly affects the size evolution of voids ; c _ { s } ^ { 2 } = 0 varies the size only by 0.1 % as compared to the homogeneous dark energy model . We also confirm that dark energy perturbation suppresses the void size when w < -1 and enhances the void size when w > -1 ( 8 ) . In contrast to the negligible impact on the size , we find that the size distribution function on scales larger than 10 { Mpc } / h highly depends on dark energy perturbation ; compared to the homogeneous dark energy model , the number of large voids of radius 30 { Mpc } is 25 % larger for the model with w = -0.9 and c _ { s } ^ { 2 } = 0 while they are 20 % less abundant for the model with w = -1.3 and c _ { s } ^ { 2 } = 0 . Key words : cosmology : large-scale structure of Universe , dark energy .