We looked at existing recommendations and supporting evidence on the effectiveness of universal screening for language and speech delay in children under 5 years of age for short- and long-term outcomes.We conducted a literature search up to the 20th of November 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 on the accuracy of the screening tests for detecting language and speech delay, the efficacy of existing interventions for children with language and speech delay, and the potential harms associated with screening and the associated interventions.Several screening tools are used to assess language and speech delay with a wide variation in their accuracy. Targeted interventions improve some measures of speech and language delay and disorders. However, there is no evidence on the effectiveness of such interventions in children detected by screening with no specific concerns about their speech or language before screening. There is no evidence assessing whether universal screening for language and speech delay in a primary care setting improves short and long-term outcomes (including speech and language outcomes and other outcomes). Finally, there is no evidence on the harms of screening for language and speech delay in primary care settings, and there is limited evidence assessing the potential harms of interventions.