The Covid-19 pandemic has caused feelings of desperation, fear, terror, anxiety while it has also brought radical changes in the quality of life and psychological health of people worldwide. The lockdown and social isolation measures due to the pandemic seem to have affected the working mothers' resilience, health, and quality of life. The purpose of this study is to examine how working mothers reacted during the Covid-19 pandemic and how the state-imposed quarantine affected their quality of life, their health, and their resilience. We designed and carried out a web-based survey in Cyprus with 208 participants, all working mothers. We administered two questionnaires, namely the World Health Organization Quality Of Life (WHOQOL)-BREF (WHO, 1998), which examines the quality of life, and the Self-evaluation Resilience Questionnaire (Resilience-Project EU, 2019), which assesses working mothers' resilience. The participants answered the questionnaires on the Internet platform Enklikanketa, from May 20 to May 30, 2020. The results showed that the state-imposed measures of social isolation in the form of quarantine had a negative impact on the psychological resilience and the quality of life of younger working mothers, of single working mothers, and of those working mothers who were residing in rural areas at the time. Working mothers who belonged to older age groups, those who continued to pursue activities and hobbies during the quarantine, and mothers who maintained a higher quality of life were affected less by social isolation measures. In conclusion, important protective and supportive factors to working mothers were family support, cooperation between their family members, the right working conditions, and job satisfaction.