On 14th March 2012 Mr Thomas Lubanga Dyilo was convicted by the International Criminal Court for the conscription of children under the age of 15 (war crimes pursuant to art. 8, par. 2, (e), (viii) of the Rome Statute). The Lubanga Dyilo case shows the wide interpteration given by the ICC to the principle of complemetarity, that seems contrary to the aims affirmed in the Preamble and those pursued by the Office of the Prosecutor. Indeed, the admissibility of the Lubanga Dyilo case appears to be inconsistent with the "proactive complemetarity" that should bring to a strict and objective interpretation of the concepts of "unwillingness" and "inability". Furthermore, the analysis is intended to demonstrate that the right moment to proceed with a formal verification of the admissibility should not come before the issue of a warrant of arrest.