Background: In France, the first COVID-19-related lockdown (17th March to 10th May 2020) resulted in a major decrease in healthcare service utilization. This raised concerns about the continuity of care for vulnerable patients. Objectives: To identify individual and organizational factors associated with the initiatives taken by French GPs to contact vulnerable patients during the lockdown. Methods: A national observational survey using an online questionnaire was conducted to document French GPs' adaptations to the COVID-19 situation, their individual and organizational characteristics, including practice type (individual, group, multidisciplinary) and size. Data were collected from 7th to 20th May 2020 using mailing lists of GPs from the study partners and GPs who participated in a previous survey. This paper analysed answers to the question exploring whether and how GPs took initiatives to contact vulnerable patients. Responses were categorized in: no initiative; selection of patients to contact with a criteria-based strategy; initiative of contact without criteria-based strategy. Multivariate multinomial logistic regression identified factors associated with each category. Key components of the reported initiatives were described by inductive analysis of verbatim material. Results: Among the 3012 participant GPs (similar to 5.6% of French GPs), 1419 (47.1%) reported initiatives to contact some patients without criteria-based strategy, and 808 (26.8%) with a strategy using various clinical/psychological/social criteria. Women GPs more often declared initiatives of contacts with a criteria-based strategy (OR = 1.41, 95% CI [1.14-1.75]) as well as GPs with more than two patients who died due to COVID-19 in comparison with those having none (OR = 1.84, 95% CI [1.43-2.36]). Teaching GPs more often used criteria-based strategies than the other GPs (OR = 1.94, 95% CI [1.51-2.48]). Compared with those working in small monodisciplinary practice, GPs working alone were less likely to implement criteria-based initiatives of contacts (OR = 0.70, 95% CI [0.51-0.97]), while GPs working in multidisciplinary practice were more likely (OR = 1.94, 95% CI [1.26-2.98] in practices > 20 professionals). Conclusion: French GPs took various initiatives to keep in touch with vulnerable patients, more frequently when working in group practices. These findings confirm the importance of primary care organization to ensure continuity of care for vulnerable people.