- All lead vocals by Marvin Gaye
- Produced by Marvin Gaye
- Members of the Detroit Symphony Orchestra Conducted and Arranged by David Van De Pitte

Background Voices:
- Marvin Gaye
- The Andantes (Jackie Hicks, Marlene Barrow, and Louvain Demps)
- Mel Farr and Lem Barney of the Detroit Lions
- Bobby Rogers of The Miracles
- Elgie Stover
- Kenneth Stover

Strings, Woodwinds and Brass:
- Gordon Staples, Zinovi Bistritzky, Beatriz Budinzky, Richard Margitza, Virginia Halfmann, Felix Resnick, Alvin Score, - - - Lillian Downs, James Waring - violins
- Edouard Kesner, Meyer Shapiro, David Ireland, Nathan Gordon - violas
- Italo Babini, Thaddeus Markiewicz, Edward Korkigan - cellos
- Max Janowsky - double bass
- Carole Crosby - harp
- Danya Hardwick, William Perich - flutes
- Larry Nozero, Angelo Carlisi, George Benson, Tate Houston - saxophones
- John Trudell, Maurice Davis - trumpets
- Carl Raetz - trombone

Instrumentation by The Funk Brothers and Solo Horns
- Eli Fountain – alto saxophone
- Wild Bill Moore – tenor saxophone
- Marvin Gaye – piano, box drum "What's Going On"
- Johnny Griffith - celeste, keyboards
- Earl Van Dyke – keyboards
- Jack Brokensha - vibraphone, percussion
- Joe Messina, Robert White – electric guitars
- James Jamerson – bass guitar "What's Going On," "What's Happening Brother," "Flyin' High," "Save the Children," "God Is Love," and the b-side "Sad Tomorrows"
- Bob Babbitt – bass guitar "Mercy, Mercy Me," "Right On," "Wholly Holy," and "Inner City Blues"
- Chet Forest – drums
- Jack Ashford - tambourine, percussion
- Eddie "Bongo" Brown, Earl DeRouen - bongos, congas

Katherine Marking – graphic design
Alana Coghlan – graphic design
John Matousek – mastering
James Hendin – Photography
Curtis McNair – Art Direction

fuente: Wikipedia