Background: The outbreak of the COVID-19 epidemic left no nation indifferent in adopting measures to fight against the spread of the disease. This survey aimed at assessing the knowledge, attitude, and practice of Cameroonians towards preventive measures against the spread of COVID-19 in Cameroon. Methodology: It was a cross-sectional online survey conducted nationwide via self-administration of a google form questionnaire in March 2020. Questionnaires were shared via Facebook and WhatsApp. Being a Cameroonian based in Cameroon was the main inclusion criteria. Data were analyzed using SPSS software. Results: Amongst the 444 respondents who completed the survey, 232(52.3%) were males and females 212 (47.7%) with the majority, 221 (49.8%) between the ages of 26 to 35. Most, (99.6%) respondents had heard of COVID-19 mainly via social media 244 (55.0%) and TV/Radio, 139(31.3%). Difficulty in breathing was the most known symptom 402(90.54%). Cameroonians are quite knowledgeable about COVID-19 (444/446 i.e. 99.6% of respondents). Less than a half, 174 (39.19%) were aware of; 13 preventive measures and over 384 (86.49%) of 7 additional measures. More than half of the participants 261(58.8%) were optimistic that the pandemic will stop if people respect the hygienic and governmental preventive measures. A majority, 91% affirmed practicing handwashingbut only 76(19.3%) did it properly. Participants demonstrated less compliance to social distancing, 230(51.8%). A significant relationship was noted between knowledge on COVID-19 and handwashing with soap (p=0.005; r=0.320) as well as the use of face masks (r=0.701, p=0.001). Conclusion: The governmental measures and hygienic preventive measures are known to Cameroonians but the compliance to these measures is moderate.