As a traditional Chinese alternative health care approach, acupuncture is gaining increasing attention and reputation in China and overseas. While becoming increasingly popular globally, some consumers and professionals still know little about the therapy and underlying mechanisms of acupuncture. Due to local superiority, there are large numbers of both clinical applications and mechanistic studies performed in China compared to countries overseas. Herein, this review attempts to give a comprehensive profile of the development, application, and mechanisms of acupuncture in treating major diseases. The number of clinical publications concerning acupuncture-treated neurological diseases, endocrine and metabolic diseases, circulatory diseases, respiratory diseases, etc. is first counted, and then, the application and therapeutic mechanisms of acupuncture on the predominant diseases in each category, including obesity, facial paralysis, sciatica, depression, hypertension, asthma, etc., are specifically discussed in this paper. The evolution of acupuncture tools and the rationality of acupoints are also discussed. This review not only summarizes the mechanisms of acupuncture but also provides useful information, such as specific acupoints and acupuncture procedures, for treating common diseases. Therefore, the current study provides useful information for both investigators and acupuncturists.