Campo de' Fiori is generally safe to visit both during the day and at night, but like any busy tourist area, it's wise to stay alert, especially in crowded settings. Watch out for common scams such as street performers requesting money after a performance or individuals asking for donations for fake charities. Be cautious in the surrounding alleys, particularly at night, as they can be dimly lit. For general safety, keep your belongings secure and avoid displaying valuables. Solo travelers should consider joining group activities or dining in public spaces to enhance their safety and enjoy the lively atmosphere.