Private detective schools teach high school or college graduates the skills needed to be a non-governmental detective, primarily through on-line or mail courses. Students learn essential knowledge about data bases, fingerprinting, internet research, surveillance technology, and legal issues. Some private detective schools are licensed through the state and therefore issue certificates of graduation that show the student has fulfilled basic requirements.

Many private detective schools teach students on the internet and/or through mail. This means there is no physical campus, but the school provides lesson plans, assignments, training, and feedback. Instructors interact virtually with the students, rather than in person. For instance, the instructor may grade papers by e-mail, conduct phone conferences, and run a message board on which a class can discuss their questions and receive guidance. Therefore, courses are structured but add a degree of flexibility to let the detective-in-training to continue their current employment.

Most of these programs through private detective schools can be completed in 6-9 months, but allow up to two years with their adaptable schedule. Their courses prepare students in research that might aid in repossessing property, locating missing persons, tracing people through credit history and state records, confirming suspicious behavior such as infidelity, and filing legal reports. Therefore, private detective schools provide materials on surveillance equipment, conducting undercover investigations, security, records on birth, death, marriage, taxes, and incarceration, DNA samples, basic legal principles of privacy, and sometimes firearms safety.

Some graduates of private detective schools are concurrently enrolled in a university, seeking a degree in Criminal Justice or similar field. However, someone who graduated from a reputable private detective course is prepared to pass a state's Private Investigator Exam where they are certified as a licensed private detective. This allows them to work in a security company as a bodyguard, a legal firm as a researcher, various levels of law enforcement, or at their own small investigator business working with individual clients as a private eye. Most private detective schools recommend additional education in firearms use and safety so graduates can be licensed to carry and use a firearm for protection.