Borderline Personality Disorder (BPD) is characterized by severe instability in mood, impulse control, relationships and sleep patterns, alongside with mild cognitive disturbances in some patients. Although research on adolescent BPD has developed over the last decade, little is known about circadian sleep-wake patterns in this population. Low compliance and cooperation frequently reported in these patients impede data collection. Therefore, research had to introduce non-invasive objective measurements such as actigraphy while minimizing attrition and resurgence of suicidal ideation. This article examined the feasibility of an actigraphic study with BPD adolescents. Eighteen BPD adolescents (13-17 years old) were recruited from a specialized outpatient mood disorders clinic and asked to wear an actigraph for nine days including two weekends. Twelve (66.7%) of the 18 BPD patients who consented kept the actigraph for an average of 11.00 days (SD: 2.04), thus completing the required 9-day period. The reasons surrounding difficulties during the experiment, such as aversive emotions during interviews, dermal irritation, fragile alliance with the research assistant, are described. The factors that contributed the most to our satisfactory compliance rate included stabilized mood before inclusion, close ties between the research and the clinical teams, rapid access to an emergency psychiatric assessment if needed.