The positive and negative syndrome scale (PANSS) and Andreasen remission criteria have contextually been used to characterize schizophrenia symptoms in clinical trials. However, few studies have investigated the relationships among the possible scores of these two psychometric tools. The present study intends to address this topic starting from a theoretical combinatorial analysis of the possible dispositions with replacement that could be generated by the two scales. The results indicated that the probability to fully accomplish Andreasen remission criteria is enclosed in a very narrow window, because of the huge amount of possible dispositions with replacement of PANSS. Conversely, the probability to accomplish the remission criteria only for the general psychopathology PANSS subscale was unexpectedly elevate. The observed differences among the probabilities to attain remission within PANSS scale are possibly related to the approach in modeling schizophrenia syndrome. The symptomatic features of individuals enrolled in clinical trials should be carefully analyzed when both PANSS and Andreasen remission criteria are used to assess schizophrenia symptoms.