The farming systems on the left bank of the Nam Ou river, a Laotian tributory of the Mekong, are described. The agricultural history of Laos is outlined. The main ethnic groups are the Punoï, the Thaï Lu, the Lao Seng, and the Ho. The main crops are upland rice, maize, poppy (Papaver somniferum). Shifting cultivation is the dominant system. The main animals are water buffalo, cattle, pigs and chickens. It is suggested to undertake development initiatives that will: (1) enhance access to buffalo; (2) improve the conditions of pig-keeping; (3) encourage the development of cash crops; (4) promote the use of animal power; (5) develop rice terraces; (6) develop forestry; and (7) diminish social differentiation. Illustrations of manual farming equipment are included. KEYWORDS: TROPAG | Papaver somniferum | Oryza sativa | Zea mays | farming systems | shifting cultivation | upland crops | livestock | animal power | equipment | constraints | farmers | LAOS