The move, announced by Nicola Sturgeon, the health secretary, will cut travelling for some patients in outlying areas.
The hospitals affected are the Gilbert Bain in Lerwick, Balfour in Kirkwall, Western Isles in Stornoway, Caithness General in Wick, Belford in Fort William and Lorn and the Isles in Oban.
It is proposed that they will carry out routine and emergency surgery; outpatient, day case inpatient and rehabilitation services; midwife-led maternity care; managing minor injuries and illnesses; and the management of patients with acute medical conditions, strokes and long-term illnesses.
Other hospitals in rural areas will also offer more services, including outpatient clinics, day-case treatment, midwifery services and treatment for minor injuries and emergencies.
To support the proposals, health workers will be given help to develop multiple skills. Extended community care teams, based in GP practices, will bring together doctors, community health nurses, midwives, social care staff and the voluntary sector. A pilot project starting in August will see a new type of doctor working in remote and rural areas, combining GP skills with specialist training in acute medicine.
This will let them divide their time between their surgery and the local hospital. A better use of technology, including video-conferencing, will also avoid the need for patients or staff to travel.
Ms Sturgeon, who announced the plan at a conference in Aviemore, has backed the recommendations of a remote and rural steering group which set out plans for enhanced roles for rural general hospitals.
About 1.5 million is being provided to back the plans. A remote and rural healthcare educational alliance gets 770,000 over three years to ensure staff get specific training.
Another 600,000 will help to recruit and train GPs for pilot projects in Fort William and Kirkwall, while 154,000 will go on a trial scheme involving flying specialist consultants to rural hospitals to provide on-site resuscitation and safe transfer for patients with life-threatening injuries or illness.
Dr Roger Gibbins, the chief executive of NHS Highland, who chaired the steering group, said: "A lot of quality work is already being done, or is in the planning stages.
"We want to continue to bring down the numbers of patients who endure regular long journeys for healthcare."