||Atypical antipsychotics are not only used for symptoms of schizophrenia, but also for the treatment of Behavioral Psychological Symptoms in Dementia. This work is focused on developing a selective, fast method for the quantitative and qualitative determination of quetiapine in Seroquel® 25mg and the generic Quetiapine 25 mg tablets. Analyses were conducted by dissolving tablets in a suitable solvent (water/ACN 50:50) and measuring the quetiapine amount using a UPLC-PDA instrument. Dissolution test, disintegration test, and thermal analysis were conducted with specific instrumentation according to the European Pharmacopea. Quantitative analysis showed that the difference between the two pharmaceutical products was about 0.055%, which is not statistically significant; qualitative analysis highlights a slight difference about the disintegration time (1 minute) and the dissolution, caused by different excipients. This is further confirmed by the thermal analysis (Differential Scanning Calorimetry). It is possible to conclude that no differences were identified among the reconstituted samples of the two different products containing quetiapine.