This paper examined the incidence of replacement adoption through varietal substitution among farmers adopting Sawah-ecotechnology rice production technology in Nigeria and Ghana. A simple random sampling was used to select 80 farmers in Nigeria and 70 farmers in Ghana. Data were collected in June 2010 with a structured questionnaire in villages where Sawah rice production technology had been introduced. In Nigeria, 30 % of the farmers practice varietal substitution with the use of WITA 3, while in Ghana 40% practice varietal substitution using jasmine and sycamore. The results from the Probit model showed that significant variables include yield (t = 4.12) participation in on farm demonstration (t = 2.77) contact with Sawah agent (t = -1.93), varietal adaptability (t = -2.29), market price (t = 2.50), lodging proneness (t = 2.45), age (t = -3.35) and farming experience (t = 2.49) in Nigeria and Ghana. It therefore implies that the issues of varietal substitution must be viewed within the prevailing socio-economic and farming system milieu of farmers in order to enhance continuous adoption and sustained profit from Sawah technology.S.Afr. Tydskr. Landbouvoorl./S. Afr. J. Agric. Ext., Vol. 39 Nr 2, 2011: 79 – 9
