Aspects of sexual dimorphism, reproduction, postnatal development, and seasonality of breeding in a solitary bathyergid rodent, the silvery mole-rat (Heliophobius argenteocinereus), as based on a field study in Malawi and on a study of animals kept in a laboratory, are reported here for the 1st time. Sex ratio in all animals (n = 173) did not differ from equality. Wild-captured males were heavier (190 ± 58 g) than females (162 ± 47 g). Mating took place during the cold and dry season (April–July), and births occurred during the hot and dry season (August–October). Mean gestation length was 95 ± 8.5 days, and mean litter size was 3.2 ± 0.9. The altricial neonates weighed 12.8 ± 2.3 g and opened their eyes about 14 days after birth. Postnatal growth rate was slow with a mean growth constant of 0.01 and a mean maximum growth rate of 0.53 g/day. The reproductive biology of H. argenteocinereus reveals characteristics of both social and solitary bathyergids. Thus, parameters believed so far to be typical of social mole-rats, such as long pregnancy and slow postnatal development, can be found in solitary silvery mole-rats as well, calling for a reevaluation of the role of reproductive biology in shaping social life.