Several studies have reported a variable benefit of valproic acid for the treatment of infantile spasm. However, valproic acid can also worsen spasms, as occurred with this child who presented with post-traumatic seizure which evolved to spasms. The child was started on antiepileptic medications, including valproic acid, despite that spasms persisting. For this reason, she was admitted for adrenocorticotropic hormone therapy. The baseline electroencephalogram showed modified hypsarrhythmia, and the laboratory workup showed thrombocytopenia, which was attributed to the valproic acid. After the valproic acid cessation, the spasms and the hypsarrhythmic pattern resolved dramatically next day, and the intended adrenocorticotropic hormone therapy was not started. Eight months later, she was still free of spasms. In conclusion, though valproic acid might have a beneficial effect in some patients with infantile spasm, it might have a negative impact on spasms in some patients which warrants its discontinuation sooner than later during spasms treatment.