The Mean Girls star was handed the punishment by Los Angeles Judge Marsha Revel earlier this month (Jul10) for violating probation on a 2007 DUI arrest by failing to attend court-ordered alcohol education classes.
She checked into a sober living facility last week (14Jul10) on the advice of her then-legal adviser Robert Shapiro, who suggested he'd be representing the troubled actress in court.
Lohan's assistant was spotted moving her belongings out of the rehab centre, Pickford Lofts, on Monday (19Jul10) - hours before it became clear Shapiro, who once represented O.J. Simpson, would not be her lawyer.
The actress returned to Beverly Hills Superior Court on Tuesday to report to jail, accompanied by Shawn Chapman Holley, who previously quit as Lohan's legal representative. She clarified that Shapiro had never been officially appointed as her client's replacement lawyer and had simply been acting as Lohan's legal consultant.
Lohan's estranged father Michael and her mother Dina were present for the brief hearing.
Michael Lohan added to the drama in court by screaming out, "I love you Lindsay" as the actress was cuffed and led away. The Mean Girls star looked scared and serious as she was taken into custody at 8.48am local time.
The 24 year old was then transported to the Lynwood Correctional Facility, the same detention centre which housed Paris Hilton in 2007 when she was found guilty on a similar charge. Nicole Richie and Daryl Hannah have also served time behind bars there.
In a press conference staged outside the jail, Steve Whitmore, spokesman for the L.A. County Sheriff's Department, told the media, "At about 10:11 this morning, Ms. Lindsay Lohan was booked into our facility to begin her sentence. She has been extremely co-operative and everything is going smoothly.
"Ms Lohan was treated just like any other (inmate). Inside it's business as usual."