Behavioural studies of sheep have shown that poor maternal behaviour by the ewe immediately postparturition can lead to reduced lamb survival and ewe production (O'Connor et al., 1985). Under field conditions, behaviour may be quantified by the maternal behaviour score (MBS) - a six-point scale assessing ewe flight distance when lambs(s) are handled for the first time, within 24 hours of birth (adapted from O'Connor et al., 1985). Greater scores are awarded to ewes remaining closer to their lamb(s). The objectives of this study were (1) to investigate the factors affecting MBS in Scottish Blackface ewes; (2) to determine if MBS affects the average weight of lambs reared or the number of lambs dying before weaning; (3) to estimate genetic and phenotypic parameters for MBS and correlations between MBS and lamb performance.