Using data from in-depth interviews with 115 women, men and couples in eastern Australia for whom family formation was a recent, current or imminent future issue, this article explores contemporary childlessness among those physically able to have children. It differentiates between those childless by choice and by circumstance, and among other themes highlights (i) the role preservation of lifestyle appears to play as a motive for deliberate childlessness following development of a life course through early adulthood that both generates lifestyle aspirations and often places parenthood on the backburner until after age 30, and (ii) the roles difficulty forming suitable relationships, women's desire for meaningful careers, and male involvement in family formation decisions play in bringing about childlessness by circumstance.Keywords Chosen childlessness AE Circumstantial childlessness AE Lifestyle opportunity costs AE Career women AE Early adult life course Re´sume´Sur la base d'entretiens approfondis mené s dans l'est de l'Australie auprè s de 115 femmes, hommes et couples pour lesquels la formation d'une famille é tait ré cente, en cours ou imminente, cet article explore l'infé condité volontaire contemporaine. La diffé rence est faite selon que l'infé condité est une affaire de choix ou de circonstances, et parmi les thè mes abordé s figurent (i) le rô le que joue le dé sir de pré server un certain mode de vie comme facteur d'explication de l'infé condité par choix, quand le cours de la vie au dé but de