The family enjoyed a holiday in the Bahamas.
Kim Kardashian West shared the first picture with her four children – and joked the shot was “almost impossible”.
The reality TV star and rapper husband Kanye West welcomed son Psalm in May.
The couple were already parents to North, six, Saint, three and one-year-old Chicago.
Kardashian West, 38, brought her children on holiday to the Bahamas and posed for a family picture on the beach.
North and Chicago wore metallic silver one-piece swimsuits to match their mother while Saint and Psalm wore swimming shorts. West was not pictured.
Kardashian West posted two pictures, both showing her struggling to get the children focused on the camera.
She captioned the snaps: “I thought taking a pic with three kids was hard OMG this is almost impossible!”
Earlier, Kardashian West shared a video of Chicago playing with a small snake.
“My brave girl Chicago”, she captioned the post.