This qualitative study was carried out with aim to design the model of sustainability of agricultural small and medium-sized businesses in Kermanshah province. The statistical population of this study consisted of the experts and key informants in Kermanshah province of which 20 persons were selected using the purposive sampling method and snowball technique. Semi-structured interviews were used to collect data. The data collection process was continued until reaching theoretical saturation or usefulness threshold of available information. The software of MAXQDA 11 was used to analyze the data. The results of the study showed that the main dimensions of the sustainability of agricultural small and medium-sized businesses were economic sustainability (including financial performance, self-reliance and financial independence, customer and market performance, and innovation and business development), social sustainability (including social communications and interactions, social responsibility and mutual social trust) and environmental sustainability (including sustainable and healthy production, conservation and optimal utilization of environmental resources and waste management). Additionally, the results of the study indicated that the main factors affecting the sustainability of agricultural small and mediumsized businesses in Kermanshah province were intra-organizational factors (including family and personal factors of the manager, marketing factors, economic-financial factors, production factors and product characteristics, factors related to business characteristics and communication and information factors) and extra-organizational factors (including political-legal, infrastructural-supportive and factors related to extension interventions).