Opisthotonus is a relatively rare, but challenging neurological symptom of spasticity or dystonia that most often results from a dramatic event such as near-drowning. The classic treatment option for opisthotonus is the oral administration of medication such as benzodiazepines and baclofen. However, results with these medications are usually not very beneficial. Numerous studies however have shown that intrathecal treatment with baclofen (ITB) is an efficient and safe treatment for generalized therapy-resistant spasticity, even in children. In this retrospective study, we describe 11 children (mean age 9 years) with pronounced opisthotonus and quadriplegia caused by different types of acquired lesions who were treated with intrathecal baclofen. Results show that in addition to an expected decrease in muscle tonus, there was also a clear improvement in patient comfort and nursing. A remarkable weight gain was observed in most patients, even when calorie intake did not change. This increase in weight might be due to a reduction in energy expenditure as a result of the decrease in spasticity. Intrathecal treatment with baclofen should be considered in every child with opisthotonus.