Sexual harassment is unwelcome verbal, visual, or physical conduct of a sexual nature that is considered severe or pervasive and either affects working conditions or creates a hostile work environment. The conduct is not considered sexual harassment if it is welcomed, so it is important for individuals who are being sexually harassed to communicate either verbally, visually, or through actions that the conduct makes them uncomfortable, and they want it to stop. Consensual dating, joking, and touching are not sexual harassment if the conduct is welcomed by the persons involved.

If a person is fired, denied a promotion, demoted, given a poor performance evaluation, or reassigned to a less desirable position because he or she rejected sexual advances, this conduct may constitute sexual harassment under federal law. Even if the conduct does not result in economic damages or a decrease in job status, it may still be considered sexual harassment if it interferes with work performance or creates an intimidating, hostile, or offensive work environment.

In California, the Fair Employment and Housing Act (FEHA) prohibits sexual harassment in the workplace. FEHA applies to private public employers, employment agencies, labor organizations, state licensing boards, and state and local governments that have one or more employees. FEHA provides protection against sexual harassment for persons who provide services pursuant to a contract. California law AB 1825 requires two hours of mandatory sexual harassment prevention education for all supervisory employees in the state.

According to the United States Supreme Court, there are two types of sexual harassment: quid pro quo and hostile environment. Quid pro quo, meaning "this for that," refers to an exchange of sexual favors and can be committed only by someone who is in a position to make or effectively influence employment decisions such as firing, demotion, and denial of promotion of an employee. 

A hostile work environment is one in which the person being harassed is so uncomfortable at work that he or her performance suffers, or he or she declines professional opportunities because they would make it impossible to avoid the harasser. One isolated instance may not constitute sexual harassment unless it is of a severe nature, such as rape or attempted rape. A number of relatively minor, separate incidents may add up to sexual harassment if the conduct creates a hostile work environment.

Conduct of a sexual nature may include verbal comments about a person's clothing, body, or behavior, jokes of a sexual nature, requesting sexual favors, repeatedly asking a person out on a date, sexual innuendos, and creating rumors about a person's sex life. Physical conduct that may constitute sexual harassment includes assault, impeding or blocking a person's path or movement, and inappropriate touching of a person or his or her clothing; this includes kissing, hugging, patting, and stroking. Nonverbal sexual harassment may be looking a person up and down, gestures or facial expressions of a sexual nature, and stalking or following someone. Visual forms of sexual harassment include posters, drawings, pictures, screensavers, and emails of a sexual nature.

Retaliation against any employee who reports sexual harassment or who cooperates when the employer investigates a claim of sexual harassment is prohibited by federal law. Employers are responsible for conducting prompt and thorough investigations of all complaints, and matters should be kept as confidential as possible. Any  person accused of sexual harassment also has a duty to cooperate in the investigation and answer questions completely and honestly, regardless of whether the allegations are true or false.

Under California law, employees have one year from an act of sexual harassment to file a formal complaint with the Department of Fair Employment and Housing. The deadlines under other states’ laws may differ.