Steganography is the science of secret message delivery using cover media. A digital image is a flexible medium used to carry a secret message because the slight modification of a cover image is hard to distinguish by human eyes. The proposed method is inspired from Zhang and Wang's method and Sudoku solutions. A selected Sudoku solution is used to guide cover pixels' modification in order to imply secret data. Because the number of possible Sudoku solutions is very large, the proposed method is more secure than Mielikainen's method and Zhang and Wang's method. From the experimental results, the visual quality of stego images produced by the proposed method is higher than 44 dB in average, which is slightly less than that of related works; however, the embedding capacity of the proposed method is 1.5 bit per pixel, which is greater than that of the related works.