Unfair competition is dishonest industrial or commercial practice.

The concept of dishonest practice is defined in Law 9.279, the Industrial Property Law.

Article 195. The following constitutes the crime of unfair competition:
I - publishes, by any means, a false statement to the detriment of a competitor, with the aim of gaining an advantage;
II - provides or discloses false information about a competitor in order to gain an advantage;
III - employs fraudulent means to divert, for personal gain or the gain of others, the clientele of another;
IV - Uses or imitates another's advertising expression or symbol in a way that creates confusion between products or establishments;
V - improperly uses another person's trade name, business title or insignia, or sells, displays or offers for sale, or has in stock, a product with such references;
VI - substitutes, with its own name or company name, in another's product, the name or company name of the latter, without their consent;
VII - claiming, as a means of propaganda, a reward or distinction that one has not received;
VIII - sells, displays, or offers for sale, in another person's container or packaging, an adulterated or counterfeit product, or uses it to trade in a product of the same kind, even if not adulterated or counterfeit, if the act does not constitute a more serious crime;
IX - gives or promises money or other benefit to an employee of a competitor, so that the employee, failing in their duty of employment, provides them with an advantage;
X - receives money or other benefit, or accepts a promise of payment or reward, in order to, failing in the duty of an employee, provide an advantage to a competitor of the employer;
XI - discloses, exploits or uses, without authorization, confidential knowledge, information or data usable in industry, commerce or the provision of services, excluding those that are public knowledge or that are evident to a technician in the field, to which access was gained through a contractual or employment relationship, even after the termination of the contract;
XII - discloses, exploits or uses, without authorization, knowledge or information referred to in the preceding paragraph, obtained by illicit means or to which access was gained through fraud; or
XIII - sells, displays or offers for sale a product, declaring it to be the subject of a patent application, or granted patent, or registered industrial design, when it is not, or mentions it, in an advertisement or commercial paper, as applied for or patented, or registered, when it is not;
XIV - discloses, exploits or uses, without authorization, test results or other undisclosed data, the preparation of which involves considerable effort and which have been submitted to government entities as a condition for approving the marketing of products.