Born in Onitsha in 1946 to parents from Agulu in Anambra State, Nigeria, he studied for one year at Ahmadu Bello University before transferring to the University of Nigeria, Nsukka as a result of pogroms against the Igbo people in northern Nigeria. During the Nigerian Civil War, the Biafran War (1967–1970), Udechukwu worked in the Propaganda Unit, and participated in the artists and writers workshops led by the poet Gabriel Okara and the artist Uche Okeke. At the end of the war, he returned to Nsukka, completing his bachelor's degree in fine arts, with a thesis on Igbo Uli mural art, in 1972. In 1973, he was appointed a Junior Fellow in the Department of Fine Arts, where he received his Master of Fine Arts in 1977. He is recognized as a leading member of the Nsukka School, originally led by Uche Okeke who served as head of the art program until 1985. While at Nsukka, Udechukwu became a founding member of the Aka Circle of Exhibiting Artists.  He was appointed Professor of Painting at Nsukka in 1986. During his tenure, his students included Tayo Adenaike, Olu Oguibe, Chika Okeke-Agulu, Marcia Kure, and Sylvester Okwunodu Ogbechie. In 1997, Udechukwu became Dana Professor of Fine Arts at St. Lawrence University, in New York State. He retired in 2018 and lives in Carson, CA.

Udechukwu frequently incorporates uli into his work, and in the 1970s he introduced nsibidi signs, as well as ink wash techniques of Chinese literati artists.[1] Many of his paintings and prints depict ordinary people; his wartime service also inspired pieces that depicted the great suffering that he saw. From the mid-1970s, his themes ranged from philosophical subjects to socio-political commentary.

Udechukwu has had more than 25 one-person exhibitions in Nigeria, England, Zimbabwe, Germany, and United States.