Bernadette Maryann Rostenkowski-Wolowitz is a microbiologist and Howard Wolowitz's wife. Bernadette is off Polish origin and a Catholic upbringing and is often seen wearing a cross necklace. Howard was introduced to Bernadette by Penny, both of whom worked together as waitresses at the Cheesecake Factory. Howard and Bernadette soon bonded over their overbearing mothers. When Howard realised this could become a lasting relationship, he suddenly proposed to Bernadette. She did not accept the proposal, but the pair continued to date.
Bernadette is generally nice and good-natured, but she has shown a dark side and admits she's a very vengeful person. When Bernadette is angry and screams, she sounds a lot like Howard's mother. After gaining her PhD in micro-biology, Bernadette was head-hunted by a big pharmaceutical company and offered a well paying job.
Towards the end of Season 3, Bernadette abruptly broke things off with Howard. It was later revealed she dumped Howard after catching him having cyber sex with "Glacinda the Troll" on World of Warcraft. Howard and Bernadette got back together early in Season 4. Howard proposed to Bernadette near the end of Season 4 and this time she accepted.
After Wil Wheaton uploaded a video from Howard's bachelor party of Raj drunkenly describing some of Howard's sexual conquests, Bernadette questioned their impending nuptials. A heart-felt apology from Howard for his past behavior won Bernadette over. As Howard's space mission approached, Bernadette decided that they should get married before he goes into space. After the couple were unable to wed at City Hall, they agreed to marry on the roof of the guys' apartment as the Google Earth satellite passed above. Sheldon, Leonard, Penny, Raj and Amy became ministers and performed the wedding.