Many bilingual school-aged children are misdiagnosed as having a Primary Language Impairment (PLI) when in reality they are in the process of learning a second language (L2). The reverse is also true. How can we differentiate between these two groups? How do we overcome the bilingual assessment challenge? Recent research has shown that children with PLI often have subtle weaknesses in their nonlinguistic cognitive processing skills. This paper will look at how we can assess these skills and establish intervention goals accordingly by looking at a review of the existing literature. Articles that have studied nonlinguistic processing skills in children with and without PLI have been examined. Deficits in processing speed, sustained attention, selective attention, cognitive control, and... working memory are often present in children with PLI. A plethora of tools exist to assess these abilities, which is why an assessment protocol is required. The tools have been grouped according to age range, the language in which they are available and the qualifications required for administration. This will facilitate the assessment of bilingual children by providing teachers, speech-language pathologists, psychologists and other professionals, assessment options founded on evidence-based practice.