The purpose of this in-depth study was to question the disparity of interpretation criteria between the different judicial operators with regard to the constitutional principle of the primacy of reality over the formalities agreed by the parties, the reality contract and the non-applicability of the statute of limitations to the action. It was found, using the jurisprudential line on the constitutional principle of the primacy of reality over formalities established by the subjects of labour relations, that despite the existence of the reality contract being proven within the process, the ruling, in some cases, condemns the defendant entity to recognise and pay the labour rights of the plaintiff worker, and in others, simply declares the limitation of the action, which implies the violation of the constitutional principles of material equality, legal certainty and effective access to the administration of justice.