Tajikistan is a poor and developing country with a very large informal activity and extensive international workers’ migration. Using the gap between household expenditure and income as an indicator of informal activity allows us to define how informal activity and migration are correlated. We find negative significant correlations between informal activities and migration. The following facts support this. The proportion of migrant workers is higher (1) in rural areas than in urban areas and (2) for low-skilled workers than for skilled and professionals. This suggests that in urban areas, a significant portion of expenditure is made through informal activities that are not officially included in the reported income. On the other hand, the low-skilled workers have less chance to engage in informal activities, so they are more likely to migrate abroad to earn more. As a concluding remark, migration is recognized as an alternative to informal sector activities in Tajikistan. This study not only defined informal activities using the difference between expenditure and income, but also clarified the correlation between informal activities and migration by separating the income of households with migrants according to the inclusion of remittances.