Preservatives are often utilized to prevent growth of bacteria and extend shell-life of personal care products (PCPs). This causes an increase in the number of cases of allergic contact dermatitis to preservatives. This study focused on the determination of two isothiazolinones (MI and MCI) in PCPs by HPLC-DAD. Different pretreatment methods were examined for different sample matrices. Recoveries were over 80% with %RSD < 6% in three studied sample matrices (wet tissue, shampoo and cream) at three different spiked levels. The method was applied to determine MI and MCI in 84 PCPs (shampoo, shower gel, cream, etc.) purchased in Ho Chi Minh City, Vietnam from March to July in 2021. MI and MCI were detected in some PCPs.