Life time psychiatric comorbidities of bipolar disorders are highly prevalent. Anxiety disorders, alcohol-substance use disorders, obsessive-compulsive disorder and attention deficit and hyperactivity disorder are the most common comorbid psychiatric conditions in bipolar disorders. Psychiatric comorbidity of bipolar disorders is strongly associated with poor treatment response, higher recurrence of mood episodes, suicide attempts, rapid-cycling, worse general functioning and quality of life. Therefore, considering the huge impact of comorbidity on the bipolar disorder illness course, treatment is usually challenging. The primary aim of the treatment in psychiatric comorbidity of bipolar disorder should be mood stabilization and prevention of mood episodes. Then, first line treatment options recommended for the specific psychiatric disorders might be preferred for the treatment of bipolar disorder comorbidity. With this rationale, quetiapine can be listed as a first line treatment for anxiety disorders comorbidity in bipolar disorders while serotonergic antidepressants and olanzapine are recommended as second line options. For the treatment of alcohol-substance use disorders comorbidity, first line mood stabilizers such as valproate and lithium and new generation antipsychotic quetiapine seem to be the leading options. Serotonergic antidepressants for obsessive-compulsive disorder and stimulants for the attention-deficit hyperactivity disorders are the key treatment choices. However, both treatment agents might cause to manic switch and mood destabilization. Thus, clinicians should be aware of these complications when prescribing in bipolar disorders comorbidity.