A 13-year-old African-American female taking sertraline for obsessive compulsive disorder was diagnosed with her first episode of atrioventricular (AV) nodal re-entrant tachycardia five days after beginning Mixed Salts of a Single-Entity Amphetamine Product (Adderall) for treatment of attention-deficit hyperactivity disorder (ADHD). She received successful cardioversion with 6 mg of intravenous adenosine, but developed a second episode of possible AV nodal re-entrant tachycardia twelve days after Adderall was reinitiated at half the previous dose. The patient had clinically similar cardiac episodes five and six months after treatment was changed to slow-release methylphenidate. Stimulant medication may evoke onset of AV nodal tachyarrhythmias in patients who have the potential to develop them, possibly in combination with a selective serotonergic reuptake inhibitor (SSRI).