This case study explores the use of a supplementary online writing program known as IQ-Write program among 18 ESL tertiary students in learning academic writing at University Teknologi MARA, Malaysia. IQ-Write program was developed based on a Framework for a Supplementary Online Writing Program derived from a Needs Analysis Study conducted on the target students as well as the pertinent learning theories and researches on writing. The data were obtained from the research instruments which include weekly observations, interviews, students' reflective journals and a set of questionnaires and were analyzed qualitatively using triangulation method. The overall findings indicate a positive result in the use of IQ-Write program in enhancing the students' writing interest and ability, training them to be critical of their writing process as well as guiding them to be autonomous in learning to write academic essays.Hence, the implication of this study shows that IQ-Write program is an invaluable supplementary online writing program for ESL tertiary students learning academic writing.