The author aims to give a survey of the recent results concerning a particular class of repetitions in words problems, namely the study of square-free words. A word is said to be square-free if none of its subwords is a square, i.e. a word of the form xx, with x a nonempty word. There are three sections dedicated to the most important new results related to square-free words: the language of square-free words, how many words are square-free and square-free morphisms. The paper fully achieves its purpose by considering the most recent works in the field: forty-seven of the total of fifty-six references are dated after 1970 and thirty-three of them are dated after 1980.