An estimated 30,000 people are expected at the three-day festival, which features Madness, Plan B, Basement Jaxx, the Vaccines, Ben Howard, Ellie Goulding and Jessie Ware.
Norman Cook – aka Fatboy Slim - who was the headline act when RockNess was first staged in 2006 is also in the star-studded line-up for this year’s festival, which features a total of more than 100 acts spread across five stages.
Basement Jaxx were the headline act on the main stage last night.
As the event got under way, the Inverness Division of Police Scotland praised the fans.
A force spokesman said: “What a day. Great atmosphere and all seem to be having a great time. Officers say Rocknessers are in great form and the event is going really well.”
But the force, which has already seized £20,000 worth of illegal drugs and reported 44 people in the region to the procurator-fiscal in the lead-up to RockNess, said Police Scotland would be taking a “robust” approach to drugs at the event.
And, as the first fans began to arrive, the force also issued a warning about two potentially dangerous drugs in circulation.
Detective Inspector Brian Mackay said: “We are aware that two extremely dangerous tablets are in circulation. These are called the ‘White Mitsubishi’ and the ‘Heineken Star’, which is yellow in colour. They are known to have extremely adverse effects on those who have taken them.”
He added: “Quality assurance is not something applied to illicit drugs, a fact that is increasingly supported by forensic analysis. Drug dealers are only interested in making money, so users can never be really sure what they are taking or what is contained in a substance when they are supplied by illegal sources.
“Users need to be aware of the dangers and understand the potentially devastating effect it can have on their health. I would urge people to avoid such products and report any information to the police on 101 or contact Crimestoppers anonymously on 0800 555 111.”