The popularity of integrating technology in language instruction and its fundamental effect on the language learning dimensions has been widely acknowledged whereas learners’ motivation and attitude are expected to be improved in a web-based Computer-assisted language learning (CALL) environment. Therefore, this paper aimed to investigate the Iranian EFL learners’ motivation to learn English and attitude in a CALL environment. The participants of this study were 120 intermediate EFL learners from two private English language institutes in Isfahan, Iran. They were divided into two equal groups; one experimental group (EG) and one control group (CG). Then, a motivation questionnaire pretest was administered out to check the participants’ motivation at the beginning of the course. As the treatment, the EG learners were taught through CALL-based instruction and the CG learners were taught traditionally. After the treatment, a posttest of motivation and an attitude questionnaire were administered. The outcomes indicated that the CALL-based instruction promoted the participants’ motivation as checked by the Motivation Questionnaire. Moreover, as measured by a 20-item A-CALL attitude questionnaire, it was discovered that the learners in the EG had positive attitudes toward using CALL-based instruction. In light of the findings, a number of conclusions are obtained and several implications are put forward.