This paper compares land degradation assessment techniques using indigenous ecological knowledge (IEK) of the Booran pastoralists and techniques used by ecologists. The study was conducted at landscape and regional levels in southern Ethiopia, where the Booran pastoral production system comprised the // / Golbo (lowlands), the // Dirre (Plateau) and the // / Liiban production systems (hereafter also referred to as regions). The study, by involving traditional range scouts in evaluating landscape and regional level environmental changes, challenges the notion that IEK is mythical and could not meet scienti®c rigour. We show that the use of common soil and vegetation indices allows comparisons of land degradation assessments between the IEK of the pastoralists and ecological techniques. Evaluation by traditional range scouts (TRSCs) and range ecologists (REs) on changes in range conditions and trends showed high correlations. Indigenous ecological knowledge was effectively used to determine landscape suitability and potential grazing capacity of individual landscapes and at regional levels. We show different perceptions in interpreting grazing suitability and potential grazing capacity. Management did not change the latter, which is an inherent property of individual landscapes, while the former could be altered. Both TRSCs and REs made comparable predictions on threats to range conditions and trends, but interpreted landscape stability differently. We suggest that integrating IEK in the ecological methods would help identify important perceptions of the pastoralists on effects of land use on local landscapes. Moreover, the value of IEK should also be considered when monitoring landscape level changes as well as when assessing degradation of the grazing lands. We hope the information in this paper will motivate policy-makers to incorporate the IEK of the pastoralists into decisions on landscape level range rehabilitation.