Despite the fact that a French (Norman) dialect has been spoken on Guernsey for over a thousand years, very little work has been done on this variety. This paper begins to redress that balance by investigating the position of the subjunctive mood in spoken and written Guernsey Norman French. As well as considering the vitality of the present and imperfect subjunctive and documenting their usage in so-called ‘grammar book’ contexts, the mood's morphology is examined, revealing in some cases survival of forms found in the medieval Norman dialect. Furthermore, it is found that the conditional tense may replace the subjunctive in certain contexts and possible reasons for this are also examined.