Akilov, 40, is accused of terrorism for stealing a beer delivery truck on Friday, April 7, and mowing down pedestrians on a busy shopping street, swerving wildly to hit as many people as possible.
Three Swedes were killed including an 11-year-old girl, as well as a 41-year-old British man and a 31-year-old Belgian woman. Ten others were injured.
Akilov, whose Swedish asylum application was turned down in 2016, had sworn allegiance to the Isis group on the eve of his assault in one of Europe's safest cities, though the jihadist group has never claimed responsibility.
After going underground, Akilov spent three months preparing the assault targeting “infidels”.
Prosecutor Hans Ihrman said the trial should provide a better understanding of “the process of radicalization” of emerging attackers, who are “marginalized in a foreign country” and take on “symbolic targets”.
He added that Akilov's case “fits into a broader framework” of jihadists.
The prosecution has formally accused him of “terrorism and attempted terrorism”.
On the first day of the trial, Akilov acknowledged the facts in the case. His lawyer Johan Eriksson said his client had planned to die in the attack.
After crashing the truck into the facade of a store, Akilov detonated an explosive device — made up of five gas canisters and nails — though it didn't explode as planned and caused damage only to the truck.
Akilov fled the scene by running into a nearby metro station, and was arrested several hours later thanks to public transport video surveillance images.
'Eager to hear'
One of the important issues in the case, which has no precedent in the Scandinavian country, is finding out whether Akilov had any active accomplices.
Investigators so far believe he acted alone. But they have recovered several smartphone exchanges he had with unidentified contacts on encrypted chat sites before, during and after the attack.
After arriving in Sweden in 2014, at the start of a big wave of migration to Europe, Akilov's application for residency was rejected in June 2016.
He later went underground to avoid expulsion and worked odd jobs in construction.
The father of four, who drank alcohol and used drugs according to colleagues and acquaintances, lived alone in Sweden. His wife and children stayed behind in Uzbekistan.
“My clients are eager to hear what he has to say, what his motives are,” Gustaf Linderholm, a lawyer representing the victims, told AFP.
“They wonder if he will express regret,” added Göran Hjalmarsson, another lawyer for the victims.
Akilov's legal team says he “intends” to answer questions about his radicalisation and his motives in court.
Prosecutors have said they will seek a life sentence and, thereafter, his expulsion from the Scandinavian country. A life sentence in Sweden varies, but is on average 16 years.
The trial is scheduled to last through May, with a verdict due in June.