Interleukin 31 (IL-31)is one of the cytokines which appears to be an important regulator of Th2 responses. Previous study has been done to determine IL-31 serums levels in atopic dermatitis (AD). However, the serum levels of IL-31 in allergic rhinitis (AR) and atopic asthma (AA) is not many reported and still unclear. The objective of this cross sectional study is to determine an association between IL-31 and other predisposing factors with allergic diseases in HRPZ II (Hospital Raja PerempuanZainab II) and HUSM (Hospital UniversitiSains), Kelantan, Malaysia. This study involved 70 patients of AD, 70 patients of AR, 70 patients of AA and 70 healthy controls from staffs and people in HUSM.Five milliliters of blood were withdrawn and centrifuged for 5 minutes at 2000 rpm to obtain the serum and analyzed for IL-31 levels by using enzymelinked immunosorbent (ELISA) kits (Human IL 31 Duoset, R&D System). Simple and multiple logistic regressions were used to analyze the association between IL-31 levels and predisposing factors among allergic diseases. The levels of IL-31 and other predisposing factors showed significant associations in smoking status, occupational exposure and area of living for AD and AR, however in AA, the significant association only found in smoking status and occupational exposure. In conclusion, we found that there were associations between IL-31 serum levels and other predisposing factors with AD, AR and AA. The findings can be the pilot study to determine IL-31 levels in allergic diseases in Malaysia.