Whether to resuscitate extremely premature infants (EPIs) is a clinically and ethically difficult decision to make. Indications and practices vary greatly across different countries and institutions, which suggests that resuscitation decisions may be influenced more by the attitudes of the individual treating physicians. Hence, gaining in-depth insight into physicians' attitudes improves our understanding of decision-making regarding resuscitation of EPIs.To better understand physicians' attitudes toward resuscitation of EPIs and factors that influence their attitudes through a systematic review of the empirical literature.Medline, Embase, Web of Science, and Scopus.We selected English-language articles in which researchers report on empirical studies of physicians' attitudes toward resuscitation of EPIs.The articles were repeatedly read, themes were identified, and data were tabulated, compared, and analyzed descriptively.Thirty-four articles were included. In general, physicians were more willing to resuscitate, to accept parents' resuscitation requests, and to refuse parents' nonresuscitation requests as gestational age (GA) increased. However, attitudes vary greatly for infants at GA 23 to 24 weeks, known as the gray zone. Although GA is the primary factor that influences physicians' attitudes, a complex interplay of patient- and non-patient-related factors also influences their attitudes.Analysis of English-only articles may limit generalizability of the results. In addition, authors of only 1 study used a qualitative approach, which may have led to a biased reductionist approach to understanding physicians' attitudes.Although correlations between GA and attitudes emerged, the results suggested a more complex interplay of factors influencing such attitudes.