Aims: This survey aimed to investigate the impact of common storage conditions on the migration of phthalate esters (PEs) including di-2-(ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), terephthalic acid (TPA), and phthalic anhydride from polyethylene terephthalate (PET) bottle into the water and to assess the potential human health risk using Monte Carlo simulation (MCS). Materials and Methods: Three different PET-bottled water brands were stored for 7 and 90 days at three temperatures: 5, 25, and >45°C. PEs were extracted from samples using the solid-phase extraction method with gas chromatography–mass spectrometry. Results: The highest concentrations were found for TPA in samples immediately after purchasing. DEHP and DBP were identified at 90 days in all of the samples. Based on the health risk assessment, the hazard quotient of four compounds in the MCS method was <1; therefore, it should not be considered as a matter of concern. However, excess lifetime cancer risk for DEHP (3.09 × 10−5) based on the maximum concentration was found to be more than 10−6. Furthermore, the adverse estrogenic effects of DEHP and DBP appeared to be significant. Conclusion: The probabilistic risk assessment revealed that high estrogen equivalence (DEHP and DBP) seemed to have adverse estrogenic effects on adults. Furthermore, adults were in carcinogenic risk of DEHP. The quality of water bottled in PET may change during the long period, and further research is recommended for the monitoring of phthalates in bottled water to ensure human health.