Somatic embryogenesis can be used to facilitate the improvement of traits in plants. The study was conducted to assess different ages of immature zygotic cowpea (Vigna unguiculata (L. Walp), “MN13” cotyledons for their ability to produce somatic embryos. Cotyledons were harvested weekly for the first 8 weeks following anthesis. After removal of their embryo axes, they were cultured in Murashige and Skoog (MS) medium containing 0.6% agar, B-5 vitamins, 3% sucrose, and 20 mg·L-1 2,4-dichlorophenoxy acetic acid (2-4D). Cotyledon explants of all the ages produced calli. The percentage of explants producing calli ranged from 32% to 92%. On transfer of the calli to similar medium containing 0.2% gellan gum instead of 0.6% agar, all ages except those from the 1-week cotyledons produced white globular somatic embryos. The largest of these embryos were 9 mm in length. The highest frequency of globular embryos was produced with the 3- to 5-week-old cotyledons.