Data of Dormer (n = 290) and SA Mutton Merino (n = 306) lambs, born by ewes which were observed continuously during lambing in 1989-1991, formed the basis of this investigation. Progeny of SA Mutton Merino ewes were heavier at birth (P ≤ 0.05) than progeny of Dormers in 1989 and 1990, but no difference was observed in 1991. Lambs given birth to by maiden ewes (2 years) were slower (P ≤0.01) to stand than progeny of adult (3-6 years) and old (≥7 years) ewes. A significant interaction between dam age and birth type was observed with regard to progress from standing to first suckling. Single lambs born to maiden ewes responded slower (P ≤0.05) than multiples. Amongst the progeny of mature ewes, singles progressed faster (P ≤0.05) than multiples, and a similar tendency was observed in progeny of old ewes. Time-lapses from birth to standing and from standing to apparently suckling declined (P ≤0.01) with an increase in birth mass. Halfsib analysis of variance heritability estimates were 0.46 ± 0.16 for the interval from birth to standing and 0.22 ± 0.12 for the interval from standing to suckling. Lambs which died subsequently were slower (P ≤0.01) to stand, and tended (P = 0.07) to progress more slowly from standing to suckling than their contemporaries which survived. It is doubtful whether these results will find application in practice, since such observations are very labour-intensive. From a scientific viewpoint it is important to take cognisance of the possibility of genetic variation in neonatal progress, suggesting that selection may have a role to play in the reduction of lamb mortality. Live-mass gain to ca. 3 days of age was found to be a reliable indicator of subsequent lamb mortality in twin and triplet lambs. An increase of 1 kg was associated with decreases of 22% in twin mortality and 43% in triplet mortality.