Lamotrigine and Sodium valproate are the widely used drugs worldwide for treatment of generalized as well as partial seizures. They are very efficacious drugs. There is a very severe skin reaction associated with Lamotrigine when co-administered with Sodium valproate called Stevens -Johnson syndrome (SJS). A case of 15-year-old girl was presented to the hospital with high grade fever (on and off) with rashes and blisters all over the body and extremities as she was on Lamotrigine (LTG) and Sodium valproate combination therapy for episodes of seizures. The dose of both the drugs was high due to which she developed SJS. Patient was started on alternative anti-convulsant for treatment of seizures and symptomatic skin and eye care drug therapy was given to the patient to reduce skin and eye lesions due to SJS. Patients on drug therapy of Lamotrigine and Sodium valproate should be properly monitored and therapeutic drug monitoring as well as adverse effect reporting is further necessary.