Intracytoplasmic sperm injection (ICSI) has become the most common method for couples with male factor infertility, and source of sperm for the procedure have evolved over time. but few have examined testicular sperm extraction vs. ejaculated sperm use for severe oligozoospermia in the same assisted reproductive technology (ART) cycle.Here, we evaluated the clinical outcomes after ICSI with testicular sperm or ejaculated in man with severe oligozoospermia in the same ART cycle. A couple who had failed the first ART cycle with ejaculated sperm, using the freshly ejaculated sperm and testicular sperm for ICSI during the second ART cycle by lack of enough sperm to fertilize in an ICSI attempt.The patient was diagnosed with severe oligozoospermia, and routine semen analysis revealed sperm concentration is less than 2 million/mL.The patient using testicular sperm versus ejaculated sperm with ICSI assisted pregnancy in the same ART cycle.We found that superior cleavage rate, number of embryos transferred and blastocyst rate with the use of testicular rather than ejaculated sperm-ICSI in the couple. The results described here suggest that use of testicular sperm may improve biologic outcomes, especially for couples with male-partner oligozoospermia who previous ICSI failures.Our case report supported the efficacy of testicular sperm preference over ejaculated sperm for ICSI in men with severe male factor infertility. It is a paradigm shift concerning the use of ejaculated sperm as the preferable source of sperm for ICSI, add to the small amount of literature on testicular sperm extraction vs. ejaculated sperm use for severe oligozoospermia in the same ART cycle.Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.