The study sites are within Marsabit North District of Kenya which is one of the most arid environments in East Africa. The social and biophysical factors used for making grazing decisions are very important for the pastoralists living in arid environment. This study sought to identify land suitability indicators and social factors considered for selecting grazing units in Gabra pastoral areas. The methods used in the study are use of calendar communication tool and assessment of grazing unit. The Gabra pastoralists consider ecological indicators when selecting new grazing unit for the goats, for example soil attributes. However, animal-based indicators are used to make decision to continue grazing or departing from a grazing unit, for instance, milk yield. In conclusion, Gabra pastoralists have considerable knowledge about their environment. They have ecological knowledge and also knowledge about their livestock. They developed this knowledge through long-term interactions with their production systems. This knowledge can be used as a starting point in the understanding of their production systems and also for initiating the development project in their region.