Nieves-Rodriguez vs. Peake[1][2] is a United States Court of Appeals for Veterans Claims case that dealt with the adequacy and weighing of medical opinions.

The Veterans Benefits Administration (VBA) denied service connection, based on a report from a VA examiner that diagnosed an anxiety reaction but did not discuss the etiology of the condition.

One doctor submitted a letter stating that he had treated the Veteran since 1995 and opined that his major depression was secondary to the service connected Guillain–Barré syndrome.

The examiner reviewed the entire claims folder and noted that previous VA neurological evaluations indicated that the Veteran exhibited "very little and very mild consequences" as a result of the Guillain–Barré Syndrome.

The Court held that a claims file review is not a mandatory requirement for private medical opinions, reasoning that the expert witness could nevertheless be informed of the sufficient facts or data, e.g., because the doctor had been treating the veteran for the illness in question.