Almost all of the flight attendant's duties are safety-related, though customer service is also important. Approximately one hour before each flight, attendants are briefed by their captain. Weather conditions, possible turbulence, flight duration, and other factors that may affect the upcoming flight are discussed in detail. They are also briefed on safety details and emergency equipment supplies relevant to the aircraft they will be flying. A list of passengers is verified and attendants are notified if any special needs passengers, small children, or VIPs will be boarding the flight.

After the briefing, flight attendants inspect the aircraft, ensuring safety equipment are in place and working properly. If a piece of equipment, such as a fire extinguisher, is found unserviceable, flight attendants must replace the item prior to takeoff. Once passengers are called to board, flight attendants assist with the boarding process. They aid any special needs passengers, children, or VIPs to ensure they receive the proper care while boarding. Tickets and seating positions are verified, and attendants check for both accuracy and possible fraudulent or stolen tickets. Attendants also monitor passengers; they are trained to detect suspicious behaviour and evidence of malicious intent to prevent hijacking or terrorism. In addition, they help passengers load carry-on baggage, checking that each adheres to aircraft or airline size and weight restrictions.

Flight attendants are also responsible for briefing the passengers on safety standards specific to the aircraft in a safety demonstration. Passengers are made aware of how to locate their nearest emergency exit, how to properly buckle their safety belts, what to do in the event of turbulence, how to operate safety vests or flotation devices, and how to use the drop-down oxygen masks. In some cases, passengers will watch a short video covering this information while the flight attendant monitors their behaviour. After the safety demonstration, attendants secure the cabin, making sure electronic devices and cell phones are turned off, carry-ons are stowed correctly, seats are in an upright position, and tray tables are stowed. The entire procedure, from boarding to takeoff, is known as Pre Take off Service.

After the plane is safely in the air, flight attendants check for passenger comfort. They deliver headphones or pillows to passengers who request them and serve food or drinks. In addition to serving the customers, flight attendants must conduct regular safety checks and listen for unusual noises. Once the plane begins its descent, attendants must ensure all trash has been removed from the cabin and seats are in their correct positions before performing a final safety check. After landing, attendants assist passengers in safely deplaning the aircraft.