Objective Mood disorders are strongly associated with suicide, the prevention of which is predicated on timely detection of suicidal activity (ideation, behaviour). Building on our previous work, we sought to determine the nature of neural responses to an emotional‐cognitive task in patients with varying degrees of suicidal activity. Method Seventy‐nine patients with mood disorders were assessed clinically and scanned using fMRI. Neural responses to an Emotional Face‐Word Stroop task were compared with 66 healthy controls. We identified regions of interest from seven key networks and examined responses to incongruent stimuli (Happy face‐‘Sad’ word; Sad face‐‘Happy’ word). Results In comparison with healthy controls, patients had differential activity during both incongruent conditions. When examining for associations with suicidal activity within the patient group, those with higher scores had decreased default mode network activity for Happy face‐‘Sad’ word manipulation, and increased basal ganglia network activity for Sad face‐‘Happy’ word manipulation, after controlling for patient characteristics. Conclusion The fMRI findings suggest that suicidal activity in patients with mood disorders may be underpinned by cognitive–emotional deficits. These findings have implications for future suicide research and for achieving a deeper understanding of suicidal activity that may ultimately inform clinical detection and management.