An invention which has industrial applicability, novelty and inventiveness may be granted to a patent in Korea, except for an invention which is likely to injure public order, morality and public health. Most of previously unpatentable subject matters, e.g., medical diagnostic methods, microorganisms and foods, are now eligible for patents.

Under the Korean Patent Law, only the first applicant is entitled to a patent when two (2) or more patent applications are made for the identical invention. If an applicant makes a priority claim when filing a patent application in Korea, the filing date for the application in Korea is deemed to be the filing date in the foreign country in applying the provisions for the patentability and the first-to-file principle.

In addition, as a member of the Patent Cooperation Treaty, Korea may be designated or elected in an international patent application under the PCT. The deadline for entering the Korean national phase has been extended to thirty one (31) months from the priority date.

After eighteen months from the filing date of a patent application have elapsed, the application is automatically published in the Patent Publication Gazette. Early publication of a patent application before eighteen (18) months from the filing date can be performed upon the request of the applicant.

Substantive examination of a patent application shall only be made when a request for examination is filed. A request for examination should be made within five (5) years from the date the application was filed. If a request for examination is of an application is not made, the application is deemed to have been withdrawn.

In order to shorten the examination period, expedited examination may be requested, especially where i) third-party infringement is occurring; ii) the expedited examination is requested based on the Patent Prosecution Highway program; or iii) a prior art search is already completed as an independent pre-requisite to qualifying for expedited examination.

According to introduction of a re-examination system, an applicant can file an amendment after final rejection while simultaneously requesting re-examination of the claims based on the amendment, without having to file a Notice of Appeal with the Intellectual Property Tribunal (IPT). This new re-examination procedure applies to applications filed after July 1, 2009.

Up to recently, medical diagnostic methods had not been patentable in Korea since such diagnostic methods had been construed as methods which had to be practiced on a human body and, therefore, were considered industrially inapplicable. However, under the recently amended Examination Guidelines, medical diagnostic methods involving an indirect contact with a human body, such as those utilizing urine or tissue samples, are patentable if they do not involve any clinical judgment, i.e., mental activity judging the status of a disease or health based on medical knowledge and experience. Medical diagnostic methods of data collection (including methods of data analysis, testing and measurement), which do not involve a direct contact with a human body, may also be patentable as long as they do not involve clinical judgment.

Numerically limited inventions, parameter inventions, system inventions, business method inventions, electronic commerce inventions, computer program inventions, single cells such as stem cells, and cloned mammals such as cloned dogs and horses are also patentable in Korea.

When the examiner finds no grounds for refusal of a patent application, the Korean Intellectual Property Office (KIPO) publishes the patent registration after the patent applicant pays the registration fee.

An issued patent can be invalidated only through an invalidation trial since the opposition system for a patent right has been repealed. The current provision relating to the invalidation trial is such that within three (3) months from the issuance of the patent, anyone (not just an interested party) can challenge the validity of the issued patent. However, after three (3) months from the patent issuance, only an interested party can file an invalidation trial.

The patent is protected for a period from the date of registration to the date of twenty (20) years from the filing date. However, for pharmaceuticals and agrochemicals inventions, special extension of terms is allowed.