Doctors' leaders said they were "not convinced" by SNP plans to enshrine guaranteed waiting times in law.
The British Medical Association (BMA) raised its concerns over legislation aimed at setting a 12-week limit for treatment. The plans could create a "litigious" culture and undermine the nature of the NHS, the body warned.
Health Secretary Nicola Sturgeon said the Patients' Rights Bill will "send out a strong signal" that patients are at the heart of the NHS. It also seeks to establish a patient advice and support service and bring in a legal right to complain.