Gender gap of student performance is one of the remaining challenge in Mozambique. This study shed light on the role of household tasks in gender gap of student performance and examine whether the gender gap comes as a result of difference in engaging household tasks. We employ the decomposition techniques with the SACMEQ III data for 3360 pupils in Mozambique. Our result by mean and quantile decomposition analysis shows that there is little evidence that the difference of household tasks engagement is the source of gender gap in performance. Though in certain condition, we find that tasks of gardening, taking care of livestock and fetching water may be a factor which causes the gender gap. We also find that the gender gap of student performance varies across the distribution.