Abstract: This research attempted to identify and analyze main resistance factors which influenced the implementation of the software process improvement project specifically companies operated in Malaysia including local and multi-national companies. The findings helped other software companies to manage future projects through the use of preventive actions or proper planning which intended to lessen anticipated problems during software process improvement projects implementation. This research used a survey instrument to gather data from 29 companies operated across Malaysia with the total of 174 business and software professionals responded. Average of 4 to 8 questionnaires were distributed to each company with the objective of getting wider views on each SPI project. The questionnaires were mainly distributed to professionals who are directly involved in SPI projects. The results showed that the most critical resistance factor is lack of adhesion and participation of the entire individual involved in SPI projects.