Groundnuts (Arachis hypogaea L.) have been found to be one of the most promising additional cash crops for diversifying Sudan agriculture. Three hundred and thirteen agronomically distinct forms have been separated from 171 varietal samples, and 121 short-maturing upright bunch types and 49 long-maturing spreading bunch types have been tested in a series of trials over several years in four climatic regions. Among upright bunch varieties, PJ121070 and Large Natal 142 appeared to be the best selections as oil and confectionery types respectively, and among spreading bunch varieties, MH.372, Beladi Bunch and NJ37 for oil, confectionery kernels and unshelled nuts respectively. A hybridization programme was started in 1959 to improve the existing varieties of groundnuts and to produce non-germinating upright bunch varieties for growing in the heavy clay soils. Inheritance studies indicated the dominance of an alternate pattern of branching, prostrate plant habit and long maturity. Dominance of testa colours was in the order of purple–red–russet brown–light brown–white. Recessive albino seedlings were observed only in crosses involving different branching pattern. There appeared to be no association between the various characters studied except maturity period, which was related to branching pattern and growth habit.