Multi-level cell programming methods are provided. A method includes providing a page buffer including first and second registers connected to first and second memory cell blocks, respectively. A least significant bit (LSB) program of each memory cell is completed. Most significant bit (MSB) data is set in a first node of the first register. An MSB program is performed. When the MSB program is performed at a first verify voltage, first data at a first voltage level is set in the first node. When the MSB program is performed at a second verify voltage, second data at a second voltage level, opposite to the first voltage level, is set in the first node. When the MSB program is performed at a third verify voltage, the first data is set in the first node. The MSB program is repeated according to the first node data.