Northern Irish English is a variety of English shaped by the influences of Irish and Scots languages, the geography, and the history of settlement of Northern Ireland. The present paper starts with a description of the historical and social background of Northern Irish English, followed by an analysis of the phonological, grammatical, and lexical features of Mid-Ulster English, which is a widespread variety of it, in two documentary films, one of which is set in Belfast, and the other in Derry. A comparison is made of the linguistic features exhibited in those two cities. The purpose of the analysis is to compare the dialectal features found in the corpus with those described in the literature and to explore whether people of different backgrounds in the documentary films exhibit the traditional features of NIE in their speech to a different extent. Certain features described in the literature did not appear in the corpus at all, whereas some others did, with varying degrees of frequency. The rarer features of NIE are found to be mostly present in the speech of people with lower levels of formal education. However, due to the limited size of the corpus it is not possible to reach a general conclusion that different groups of people exhibit the traditional dialectal features to a different extent.