In 2014, there were 36.9 million people worldwide living with human immunodeficiency virus (PLWH), of whom 17.1 million did not know they were infected. Whilst the number of new human immunodeficiency virus (HIV) infections has declined globally since 2000, there are still regions where new infection rates are rising, and diagnosing HIV early in the course of infection remains a challenge. Late presentation to care in HIV refers to individuals newly presenting for HIV care with a CD4 count below 350 cells/µl or with an acquired immune deficiency syndrome (AIDS)-defining event. Late presentation is associated with increased patient morbidity and mortality, healthcare costs and risk of onward transmission by individuals unaware of their status. Further, late presentation limits the effectiveness of all subsequent steps in the cascade of HIV care. Recent figures from 34 countries in Europe show that late presentation occurs in 38.3% to 49.8% of patients newly presenting for care, depending on region. In Switzerland, data from patients enrolled in the Swiss HIV Cohort Study put the rate of late presentation at 49.8% and show that patients outside established HIV risk groups are most likely to be late presenters. Provider-initiated testing needs to be improved to reach these groups, which include heterosexual men and women and older patients. The aim of this review is to describe the scale and implications of late presentation using cohort data from Switzerland and elsewhere in Europe, and to highlight initiatives to improve early HIV diagnosis. The importance of recognising indicator conditions and the potential for missed opportunities for HIV testing is illustrated in three clinical case studies.