We looked at existing recommendations and supporting evidence on the effectiveness of vitamin K given after birth in preventing the haemorrhagic disease of the newborn (HDN).We conducted a literature search up to the 10th of December 2019 by using key terms and manual search in selected sources. We summarized the recommendations and the strength of the recommendation when and as reported by the authors. We summarized the main findings of systematic reviews with the certainty of the evidence as reported.All newborns should receive vitamin K prophylaxis, as it has been proven that oral and intramuscular prophylactic vitamin K given after birth are effective for preventing classical HDN. There are no randomized trials looking at the efficacy of vitamin K supplement on late HDN. There are no randomized trials comparing the oral and intramuscular route of administration of prophylactic vitamin K in newborns. From older trials and surveillance data, it seems that there is no significant difference between the intramuscular and the oral regimens for preventing classical and late HDN, provided that the oral regimen is duly completed. Evidence assessing vitamin K prophylaxis in preterm infants is scarce.