Its 11th International Classification of Diseases (ICD) will include the condition "gaming disorder".
The draft document describes it as a pattern of persistent or recurrent gaming behaviour so severe that it takes "precedence over other life interests".
Some countries had already identified it as a major public health issue.
Many, including the UK, have private addiction clinics to "treat" the condition.
The last version of the ICD was completed in 1992, with the new guide due to be published in 2018.
The guide contains codes for diseases, signs and symptoms and is used by doctors and researchers to track and diagnose disease.
It will suggest that abnormal gaming behaviour should be in evidence over a period of at least 12 months "for a diagnosis to be assigned" but added that period might be shortened "if symptoms are severe".
Symptoms include:
impaired control over gaming (frequency, intensity, duration)
increased priority given to gaming
continuation or escalation of gaming despite negative consequences
Dr Richard Graham, lead technology addiction specialist at the Nightingale Hospital in London, welcomed the decision to recognise the condition.
"It is significant because it creates the opportunity for more specialised services. It puts it on the map as something to take seriously."
But he added that he would have sympathy for those who do not think the condition should be medicalised.
"It could lead to confused parents whose children are just enthusiastic gamers."
He said he sees about 50 new cases of digital addiction each year and his criteria is based on whether the activity is affecting basic things such as sleep, eating, socialising and education.
He said one question he asked himself was: "Is the addiction taking up neurological real-estate, dominating thinking and preoccupation?"
Many psychiatrists refer to the Diagnostic and Statistical Manual of Mental Disorders (DSM), the fifth edition of which was published in 2013.
In that, internet gaming disorder is listed as a "condition for further study", meaning it is not officially recognised.
Lots of countries are grappling with the issue and in South Korea the government has introduced a law banning access for children under 16 from online games between midnight and 06:00.
In Japan, players are alerted if they spend more than a certain amount of time each month playing games and in China, internet giant Tencent has limited the hours that children can play its most popular games.
A recent study from the University of Oxford suggested that, although children spend a lot of time on their screens, they generally managed to intertwine their digital pastimes with daily life.
The research - looking at children aged eight to 18 - found that boys spent longer playing video games than girls.
Researcher Killian Mullan said: "People think that children are addicted to technology and in front of these screens 24/7, to the exclusion of other activities - and we now know that is not the case."
"Our findings show that technology is being used with and in some cases perhaps to support other activities, like homework for instance, and not pushing them out," he added.
"Just like we adults do, children spread their digital tech use throughout the day, while doing other things."
