The :substitute command searches for a text pattern, and replaces it with a text string. There are many options, but these are what you probably want: :%s/foo/bar/g Find each occurrence of 'foo' (in all lines), and replace it with 'bar'. :s/foo/bar/g Find each occurrence of 'foo' (in the current line only), and replace it with 'bar'. :%s/foo/bar/gc Change each 'foo' to 'bar', but ask for confirmation first. :%s/\ /bar/gc \> Change only whole words exactly matching 'foo' to 'bar'; ask for confirmation. :%s/foo/bar/gci Change each 'foo' (case insensitive due to the i flag) to 'bar'; ask for confirmation. :%s/foo\c/bar/gc is the same because \c makes the search case insensitive. This may be wanted after using :set noignorecase to make searches case sensiti