The teens acted as bridesmaids as Brandon Jenner's said 'I do' to Leah Felder, daughter of former Eagles guitarist Don Felder, in Kauai.
Kendall, 16, wore a flowing dress which exposed her back while Kylie, 14, was in a pale blue frock. Both had flowers in their hair.
Big day: Kendal and Kylie Jenner were bridesmaids at their half-brother Brandon's wedding in Kauai, Hawaii. Stepmother Kris also attended
Here come's the bride: Bruce Jenner's son Brandon married Leah Felder
Father of the groom Bruce watched on proudly while Brandon's famous stepmother Kris also attended, wearing a pink floral halterneck dress to the nuptials.
Kim Kardashian and her sisters Khloé and Kourtney decided not to jet to Hawaii for the occasion, fuelling speculation that they 'snubbed' the big day.
Instead, the threesome were spotted going to lunch together in Sherman Oaks, California.
According to Radar Online, Kim, Khloé and Kourtney refused to go to the wedding, but a source dismissed this, telling them: 'There is no animosity, but the Kardashian girls just aren't super close to the Jenner boys.'
Too busy: Kourtney, Khloe and Kim Kardashian went for lunch in Sherman Oaks, California, yesterday
Kim kept her well wishes simple, by tweeting to her 14,822,171 followers: 'Congratulations to my step brother and his gorgeous new wife!'
Meanwhile, Khloé wrote on her blog: 'I just wanted to send a HUGE congratulations and so much love to my brother Brandon and his fiancé/soon-to-be wife Leah. Wishing you both all the happiness in the world!'
Kourtney added on her blog: 'I want to wish a huge congratulations to my step brother Brandon and his stunning fiance Leah who are marrying today. Sending my love to you both.'
Just married: The couple looked blissfully happy on their big day
Family affair: Father of the groom Bruce Jenner with David Foster, who was Brandon's stepfather during his 14-year marriage to Bruce's ex Linda, and right, Brody Jenner
However, the ladies clearly didn't care enough the big day to fly to Hawaii and watch Leah walk down the aisle.
But luckily, the rest of Brandon's family were there including his father Bruce Jenner, his wife Kris and their teenager daughters Kylie and Kendall.
The foursome were spotted swigging back POG juice - a tropical drink made from passionfruit, orange and guava fruits - as they arrived at their hotel in Kauai.
Brandon is one of Bruce's three sons from his second marriage to Linda Thompson, who was also in Hawaii.
Linda's ex-husband David Foster, the multimillionaire songwriter to whom she was married from 1991-2005, was also there.
Pretty in pink: Kris wore a floral dress for the occasion
The former athlete was first married to Chrystie Crownover, with whom he had two children Burt and Cassandra.
His third son, Brody, was born in 1983 but less than ten years later Bruce wed Kris - who already had four children with her former husband Robert Kardashian.
In 1995, Kris gave birth to hers and Bruce's first daughter Kendall, and two years later they welcomed Kylie into the world.
Happy times: Kylie Jenner posted a photo of her and her sister Kendall with Brandon and Leah (centre)
We are family: Kris and Bruce Jenner made sure they were at the wedding with their teenage daughters Kylie and Kendall
Back to reality: Kris and the girls looked well-rested when they returned to Los Angeles following the trip
Homeward bound: Kylie and a rather luminous Bruce were spotted arriving back into LAX