This is a study focused on describing the effect of I-SPELL on pre-service science teachers’ attitude towards inquiry-based activities across sex, specialization, High School graduated from and type of High School Curriculum attended. The study used a researcher-made attitudinnaire to measure pre-service science teachers’ attitude towards inquiry-based activities before and after exposure to I-SPELL. The researcher-made attitudinnaire used as data-gathering instrument underwent expert validation and pilot testing to determine its validity and reliability (cronbach’s =.9476). Mean and standard deviation were used for descriptive analysis of data while T-tests for independent and paired samples and One-way ANOVA were used for inferential analysis. All inferential tests were set at 0.05 level of significance.The attitude of the participants toward inquiry-based activities was generally “positive” before and after the intervention. Inferential analysis of data showed that there were no significant differences in the pre-service science teachers’ attitude towards Inquiry-Based activities before and after exposure to I-SPELL across sex, specialization, High School graduated from and type of High School Curriculum attended. However, a significant difference was noted in terms of the Subject’s attitude towards Inquiry-Based Activities after exposure to I-SPELL when classified as to specialization where in the attitude of BSEd Biology students was significantly lower than that of Physics and Physical Science Majors while the attitude of the two later groups (Physics and Physical Science Majors) did not differ significantly with each other.