The COVID-19 pandemic has caused devastating impacts globally. To mitigate virus spread, Israel imposed severe restrictions during March–April 2020. An online cross-sectional survey was conducted in April 2020 among current and ex-smokers to explore changes in smoking behaviour and home-smoking rules during this period. Bivariate analysis and multivariate logistic regression examined associations between sociodemographic characteristics and perceived risk of infection and quitting smoking during the initial COVID-19 period. Current smoking was reported by 437 (66.2%) of the 660 participants, 46 (7%) quit during the initial restriction period, and 177 (26.8%) were ex-smokers. Nearly half (44.4%) of current smokers intensified their smoking, and 16% attempted to quit. Quitting during the COVID-19 period was significantly associated with higher education (adjusted odds ratio (aOR): 1.97, 95% CI: 1.0–3.8), not living with a smoker (aOR: 2.18, 95% CI: 1.0–4.4), and having an underlying chronic condition that increases risk for COVID-19 complications (aOR: 2.32, 95% CI: 1.1–4.6). Both an increase in smoking behaviour and in attempts to quit smoking during the initial COVID-19 pandemic were evident in this sample of adult Israeli smokers. Governments need to use this opportunity to encourage smokers to attempt quitting and create smoke-free homes, especially during lockdown conditions, while providing mental and social support to all smokers.