Prell was born in Los Angeles, California, and graduated from Los Angeles High School in the summer of 1942. At the end of his sophomore year at UCLA he enlisted in the US Army. In 1944, age 19, he graduated from Officer Candidate School (U.S. Army), Ft. Benning, Georgia, and was commissioned a 2nd Lieutenant, Infantry. Serving in the European Theater of Operations in command of the second platoon of the Anti-Tank Company, 422nd Regiment, 106th Division, during the Battle of the Bulge, December 1944, he was wounded and captured.  In March 1945, he was liberated by Task Force Baum during its “Raid” at Oflag XIII-B (which General George S. Patton, Jr. reported as the only mistake he made during World War II). Prell’s freedom lasted only a few days as he was recaptured after attempting to locate friendly forces. A month later, he escaped from a POW camp south of Nuremberg, and found his way to freedom. Captured at the same time as Prell, was Richard Bordeaux Parker, who commanded the first platoon of the Anti-Tank Company. 
After the war he resumed undergraduate studies at UCLA and graduated in 1948. While at UCLA he was an active member of the American Veterans Committee. Prell was a Ph.D. candidate in Psychology with Hans Eysenck’s Program Research Team at the University of London from 1948-1951. It was here that he learned to program Hollerith punched card tabulation machines, the forerunner of today’s digital computers.
Marriage and family
During the 1950s Prell worked with Rand Corporation futurist Herman Kahn, who later founded the Hudson Institute in New York. Also in the 1950s he was associated with many of the early designers of high-speed computer input-output devices, analog to digital converters and digital display plotters, including Benson-Lehner Corporation. In 1957, working with Thompson Publications, he created Datamation, the first magazine dedicated solely to the emerging computer-data-processing industry.  In 1961, he was president, and the major shareholder of Electro Radiation, Inc, a Santa Monica, California firm specializing in molecular electronics and electroluminescence.  Later he founded and served as President of two venture capital firms: 1967 Union Ventures (a subsidiary of the Union Bank N.A.) and in 1980 Imperial Ventures (a subsidiary of Imperial Bank of California). During his association with Union Bank, he was responsible for producing the bank’s first and only 30-year Strategic Plan.
Over the course of his career Prell pursued long-standing interests in both Edward John Trelawny, a novelist and friend of Percy Bysshe Shelley and Lord Byron, and Pierre Laval, Prime Minister of France in the 1930s and again during the Vichy era. In the course of Prell's research, he authored three journal articles and five books and developed extensive collections of material by and about Trelawny and Laval. These research materials have been donated to two southern California libraries:
- The Edward John Trelawny Collection, including one of the original notebooks of Edward Ellerker Williams, an associate of Shelley, is in the Special Collections of the Honnold/Mudd Library, Claremont Colleges, Claremont, California.
- The Pierre Laval Collection resides in Special Collections of the UCR Libraries, University of California, Riverside, Riverside, California.
Prell received the UCLA University Service Award in 1977. 
- The Inheritance of Neuroticism: An Experimental Study, Hans. J. Eysenck and Donald B. Prell, The Journal of Mental Health, Volume XCVII, July, 1951, pp. 441–465
- Economic study of the Seychelles Islands, D. B. Prell. 1965,
- The Sinking of the Don Juan Revisited, Donald B. Prell, Keats-Shelley Journal, Volume LVI, 2007, pp. 136–154
- Discovering Byron’s Boat (the Bolivar), Donald Prell, The Byron Journal, Volume 35, No.1, 2007, pp. 53–59
- The Untold Story of the Survival of the Penn Central Company, Donald B. Prell, Strand Publishing, 2003 Open Library
- Trelawny, Fact or Fiction, Donald B. Prell, Strand Publishing, 2008,
- Sailing With Byron from Genoa to Cephalonia, Donald B. Prell, Strand Publishing, 2009 Open Library
- Lord Byron --- Coincidence or Destiny, Donald B. Prell, Strand Publishing, 2009 Open Library
- Biography of Captain Daniel Roberts, Donald B. Prell, Strand Publishing, 2010 Open Library
- Patton (Ordeal and Triumph) by Ladislas Farago, 1964, p. 790. (Originally from Patton’s personal Journal, published posthumously in the Saturday Evening Post in August 1949)
- "SM Firm Acquires Vacuum Technology". Evening Outlook. Retrieved 31 August 2015.
- "Biographical Information". Mendeley Ltd. 2014. Retrieved 2014-07-11.
- "Edward John Trelawny Collection". Special Collections at The Claremont Colleges Library. 2007-12-12. Retrieved 2014-07-11.
- "Pierre Laval Collection". UCR Libraries. Retrieved 2014-07-11.
- UCLA Library Catalog - Titles