Cold calling is the solicitation of business from potential customers who have had no prior contact with the salesperson conducting the call. It is an attempt to convince potential customers to purchase the salesperson's product or service. Generally, it is an over-the-phone process, making it a form of telemarketing, but can also be done in-person by door-to-door salespeople. Though cold calling can be used as a legitimate business tool, scammers can use cold calling as well.

Cold calling has developed from a form of giving sales pitch using a script into a targeted communication tool. Salespeople call from a list of potential customers that fit certain parameters built to help increase the likelihood of a sale. This modern cold calling, sometimes called "warm calling", tries to "dig deeply to understand" the potential customer.

With the development of newer technology and the Internet, cold calling has gained some criticism. Jeffrey Gitomer wrote in a 2010 article for The Augusta Chronicle that "the return on investment on cold calling is under zero." Gitomer believes that cold calling will only annoy customers and will not attract business. Gitomer also believes that referral marketing is a better form of selling and marketing. According to Gitomer, there are "2.5 basic understandings of a cold call":

Cold calling has also been used by scammers. One such example was when groups of impostors posed as members of the Microsoft support team. The impostors called several homes from a database of Microsoft owners. The Microsoft customers were then told that there was a virus on their computers, and in order to fix it, they had to download a specific program. The program gave access to the computer files for the impostors. Cold calling has been a hallmark in the proliferation of boiler room scams selling fraudulent investment and sports betting schemes from Australia's Gold Coast.

Many countries have rules and regulations that limit and control how, when and whom companies can cold call. These rules and regulations are often implemented by government bodies that deal with telecommunication laws in their specific country.

The United States telecommunication laws are developed and enacted by the Federal Trade Commission (FTC). The FTC aims to "puts consumers in charge of the number of telemarketing calls they get at home". The United States, along with many individual states, have enacted various "Do Not Call" lists. These lists are based on the national US Do Not Call List which was enacted in 2003. Every month, since January 2005, companies are required by law to check the "Do Not Call List" database. They are required to remove the registered numbers from their leads lists. However the "Do Not Call List" has certain limitations. Even if a person is registered for the "Do Not Call List", certain organizations can still call. These organizations include:

The FTC has also set certain regulations on when one can be called. Cold calling can only be done in between 8 a.m. and 9 p.m. The caller is also required by law to tell the customer who they are and what organization they represent. This includes clarifying if the organization is a for-profit organization or charity. The salesperson also must reveal all information about the product they are selling. This means that they are legally required not to lie.

Many other government organizations monitor cold calling within their jurisdiction including the U.S. Securities and Exchange Commission (SEC). The SEC specializes in monitoring cold calling that deals with stocks, specifically stockbrokers. When investing over the phone, the SEC states that written banking information must be given. This means that an investment cannot be made over the phone.