Judge Michael Pastor gave Murray the maximum sentence yesterday, saying the evidence in the case showed a "continuous pattern of lies and deceit" by the doctor. Murray, 58, was convicted of involuntary manslaughter earlier this month.
Several members of the Jackson family attended the sentencing hearing.
In a statement, the family said they hope Murray's punishment,"Reminds physicians that they cannot sell their services to the highest bidder and cast aside their Hippocratic oath to do no harm."
Murray will likely serve only half his sentence due to automatic credit for good behaviour, Los Angeles County Sheriff's spokesman Steve Whitmore said.
The judge gave a 30-minute explanation of why he was sentencing Murray to the maximum jail time, even though the doctor was technically eligible for probation.
Superior Court Judge Michael Pastor reprimanded Murray for his "horrific violation of trust" in caring for the pop superstar and called the heavy use of propofol "medicine madness".
Murray treated Jackson like a "medical experiment," the judge said, which factored into his decision to hand down the maximum sentence.
"Four years is not enough for someone's life," Katherine Jackson, the singer's mother, said after sentencing. "It won't bring him back, but at least he got the maximum." Jermaine Jackson said he would miss playing music with his brother Michael and being a family.
"One hundred years is not enough," he said. Several members of Jackson's immediate family attended the sentencing, including his mother Katherine and siblings LaToya, Jermaine, Randy and Rebbie.
Murray's mother and girlfriend also attended proceedings. Michael Jackson's oldest two children, Prince and Paris were "extremely pleased and relieved" that Murray was found guilty of killing their father.
As soon as the verdict was read in court, Katherine Jackson met privately with Deputy District Attorney David Walgren, and "broke down in tears as she thanked him for bringing Michael's children justice.
It was very emotional.
Walgren had hammered home the point to the jury that Michael's three children didn't have a father because of Conrad Murray.
Katherine gave the DA one final hug before leaving and said, "Now I can go home and tell the children that he has been found guilty."
Katherine wanted to get home as quickly as possible after the verdict had been announced so she could tell Prince, Paris, and Blanket that Murray was found guilty and behind bars.