Attention deficit hyperactivity disorder (ADHD) is a common psychiatric disorder with estimated global prevalence rates between 3% and 5% in children and 2.5% in adults, depending on the classification system used. The psychostimulant methylphenidate is one of the most frequently used medications for ADHD. In this analysis article we describe shortly the evidence in the field, an application for inclusion of methylphenidate on the WHO Model List of Essential Medicines, the comments raised to the application and the WHO Expert Committee’s decision. The application of getting methylphenidate on the WHO list was overzealous in reporting potential benefits, without highlighting key uncertainties and harms. Decisions encompassing medicines candidate to the WHO Model List should not be based on speculation about potential benefits and should fully incorporate areas of uncertainties. Even though methylphenidate has been used for over 60 years, the evidence concerning the benefits of this medication in children, adolescents and adults with ADHD is uncertain. The decision of the committee was to not include methylphenidate in the WHO Model List of Essential Medicines ‘due to uncertainties in the estimates of benefit, and concerns regarding the quality and limitations of the available evidence for both benefit and harm’.