Protesters said they were ready to go to jail, and a cheer went up from supporters as thirteen people were arrested.
It happened at pipeline company TransCanada's downtown offices after protesters sat down with signs by the front entrance.
Protester Ben Ball says he's worried about the oil sands crude the Keystone XL pipeline would bring to the Gulf Coast from Canada.
"It's the dirtiest fuel this side of coal. We need to spend all of our efforts and all of our money on cleaner fuels, not dirtier fuels."
Houston police arrest protester in front of TransCanada's downtown offices.
And protester Jackie Rundstein says it's not fair that oil companies are using eminent domain to route the pipeline across private property.
"Why should this be brought down from Canada for us to refine and all the things that happen in pipelines along the way from Canada to here? It's all for the profit of a big corporation."
Sections of the pipeline have already been constructed in Texas, and President Obama will have to decide whether the pipeline can cross into the U.S. from Canada.
Supporters of the pipeline say it would create jobs and help the U.S. achieve energy independence.