Background: Health care professionals must stay updated with the latest guidelines for basic life support (BLS) and advanced cardiac life support (ACLS) to effectively assist patients during cardiac emergencies. Since its launch in 2018, the Ghana Heart Initiative has significantly enhanced the skills and knowledge of health care professionals in managing cardiovascular diseases, including cardiac emergencies. Objective: This study aims to assess the knowledge and skills of BLS and ACLS among health care professionals immediately after training in Ghana. Methods: This cross-sectional, training-based study involved 541 and 302 health care professionals trained in BLS and ACLS, respectively. Among them, 229 BLS and 124 ACLS-trained participants completed the questionnaires immediately after the training, and their data were included in the final analysis. Knowledge was assessed using a standardized questionnaire and an instructor-led skills evaluation based on the updated 2018 and 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Results: This study shows that 74.6% (171/229) of the health care professionals had adequate knowledge and skills in BLS. Those working in tertiary health care facilities were 80% less likely (adjusted odds ratio [AOR] 0.20, 95% CI 0.07-0.59; P=.003) to have adequate BLS knowledge and skills than those in primary health care facilities. Health care professionals from regions such as Volta and Oti were 4.94 times more likely to have adequate BLS knowledge and skills compared to those from Bono East (AOR 4.94, 95% CI 1.17-20.80; P=.03). Over 73.3% (91/124) of health care professionals had adequate knowledge and skills in ACLS. Males were 7.05 times more likely (AOR 7.05, 95% CI 2.69-18.46; P