This is an open label trial with primary objective to provide early access to TMC125 for treatment-experienced HIV-1 infected patients who have failed multiple antiretroviral (ARV) regimens and have limited treatment options with currently approved ARVs. The secondary objective of this trial is to gather information on the safety and tolerability aspects of TMC125 in combination with other ARVs. Available efficacy data will also be collected. Patients should be at least 3-class experienced or 2-class experienced with primary non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance. They should also have previously received 2 different protease inhibitor-based regimens (low-dose ritonavir is not counted as a protease inhibitor (PI) regimen), be on a treatment interruption or not be virologically suppressed on their current regimen, and not be able to use currently approved NNRTIs due to resistance (primary or acquired) and/or intolerance. Patients must also meet all in- and exclusion criteria. TMC125 (200mg twice daily) will be provided once the patient has been confirmed eligible for entry. Once treatment with TMC125 in combination with other ARVs has been initiated, patients must be instructed to follow the recommended visit schedule based on routine clinical care. Safety and tolerability of the entire antiretroviral therapy (ART) regimen, including TMC125, should be monitored by the investigator as per standard clinical practice. However, it is recommended that visits be planned 4 and 12 weeks following initiation of TMC125 in combination with other ARVs and every 12 weeks thereafter while on therapy during this trial. Adverse events (AEs) leading to treatment interruption or discontinuation and all serious adverse events (SAEs), with the exception of Acquired Immunodeficiency Syndrome (AIDS) defining illnesses (CDC class C) unless fatal or considered to be related to TMC125, will be collected. Other adverse events will be collected only if required as per local regulations. The background ARVs may be changed at any time during the trial, at the discretion of the investigator due to the development of resistance, intolerance, toxicity, etc. while continuing treatment with TMC125 if in the investigator's assessment the patient still benefits from treatment with TMC125. If changes in the background regimen are made, it is recommended that a follow-up visit be planned 4 weeks after the change in therapy. Treatment with investigational medication will be continued until virologic failure, treatment-limiting toxicity, subject lost to follow-up, patient's withdrawal, pregnancy, discontinuation of TMC125 development or when TMC125 has become commercially available in the patient's country. Patients will be instructed to orally take two 100 mg tablets of TMC125 following a meal every 12 hours. TMC125 (200 mg twice daily) must be used in combination with other antiretroviral drugs. Treatment with investigational medication will continue until virologic failure, treatment-limiting toxicity, patient lost to follow-up, withdrawal, pregnancy, discontinuation of TMC125 development or when TMC125 becomes commercially available in the patient's country.