Most people diagnosed as terminally ill with organ failure or dementia either fail to request any specialist end-of-life treatment or are not identified as needing it, researchers have found.
But three-quarters of patients suffering from cancer do get specialist care, according to the study from Marie Curie Cancer Care, Edinburgh University and NHS Lothian.
Anne Finucane, co-author of the report from Marie Curie, said: "It is clear from our study that most people with a non-cancer diagnosis are not identified for palliative care before they die.
"These patients are missing out on the benefits that a palliative care approach could provide including symptom relief as well as social, psychological and spiritual support. In Scottish society, we need to promote a culture that is less afraid of discussing death and dying.
"Patients and healthcare professionals should be encouraged to talk more openly about death and dying so that patients have a better understanding of what lies ahead, and are provided the support they need when making important decisions relating to their future care.
"More openness around death and dying will help patients to live as well as they can in the last months, weeks and days of life."
Researchers said GPs found such care to be easier to introduce for cancer patients, who often had a clear terminal decline, but harder for those with other life-threatening illnesses, such as liver failure.
NHS Lothian is currently redesigning its palliative care systems with the help of Marie Curie. This could see fewer patients dying in hospitals and more choosing the end their life at home. It is also likely more volunteers will be on hand to offer support to those who are terminally ill.
Services to be examined include hospice day services and care homes. New ways of discharging dying patients, so that they can die at home if they choose, could be introduced.
Professor Scott Murray from Edinburgh University, said he believed the current system worked well for patients with cancer.
But he added: "People with other conditions often miss out on this opportunity for more psychological, emotional, spiritual and practical support.
"Better and earlier identification of all patients who may benefit from these services is vital so that they can receive the care they need, and not slip through the net.
"It's clear that if we are going to better improve the chances for everyone with both cancer and non-cancer diagnoses to benefit from palliative care, doctors and nurses should be comfortable and able to talk to and listen to patients when they want to talk about death and dying."
"The big challenge for patients is to talk about how you feel, and what you would like if you become ill, so that your relatives and friends and doctors know what to do."
Peter McLoughlin, co-author of the report from NHS Lothian said: "Health and social care professionals in all settings across Lothian already offer supportive care throughout the patient pathway from clinical assessment to diagnosis, treatment and follow-up.
"The findings from this study emphasise that many more people, especially those with non-cancer conditions, may benefit from a more explicit recognition of palliative care needs, at an earlier stage in the pathway as part of care planning."
The study, published in the European Journal of Palliative Care, is the first of its kind in the UK to look how patients are identified for palliative care.
The research team investigated 684 cases from nine GP practices.