A nonvolatile memory device includes multi-level cells. A sensing method of the nonvolatile memory device includes: precharging a bit line and a sense-out node during a first precharge interval; identifying a first state of a selected memory cell, by developing the sense-out node during a first develop time and sensing a first voltage level of the sense-out node; precharging the sense-out node to a second sense-out precharge voltage; and identifying the first state of the selected memory cell from a second state adjacent thereto, by developing the sense-out node during a second develop time different from the first develop time and sensing a second voltage level of the sense-out node.