The aim of this study was to investigate pathway relationship of personality characteristics and alexithymic traits in OCD symptoms of obsession, and compulsive behavior of washing and checking. Two-hundred and seventy patients diagnosed with OCD were consecutively recruited from the psychiatric outpatient department of a teaching hospital. Structural equation modeling showed those more neurotic, less extraverted and with higher levels of alexithymia difficulty identifying feelings (DIF), difficulty describing feelings (DDF) and externally oriented thinking (EOT) were more likely to develop obsessive thoughts. Those less extraverted was more prone to develop washing compulsions, and those more neurotic were more likely to develop checking compulsions. EOT was the only alexithymic trait to have no gender difference within this group of patients with OCDs. The different personality and alexithymic trait pathways found between OCD obsession, washing and checking symptoms provide support that they may be different subtypes within the OCD diagnosis. Obsession was associated with washing, but not checking. Furthermore, no gender difference was found between the obsession and compulsive symptoms. Extraversion and neuroticism can be used to differentiate washing and checking, and alexithymia to differentiate washing and obsessions. This should be taken into consideration for intervention targeting patients with different OCD symptoms.