Bert och brorsorna (Swedish: Bert and the brothers) is a diary novel, written by Anders Jacobsson and Sören Olsson and originally published in 1995, it tells the story of Bert Ljung from 7 June to 23 August during the calendar year he turns 12 during the summer vacation between the 5th and 6th grade at school in Sweden.

Bert Ljung finishes the 5th grade, and Klimpen will move to Motala.

Despite fearing her brothers, Bert continues meeting Nadja Nilsson.

Bert's family also goes on a trip to Denmark in July, and on board the boat they meet a family where a 6 years old child asks Bert how many political parties are in the parliament of Sweden.

In August Bert, Åke and Lill-Erik sleep in a tent in the giant woodlands behind the hil, and when the book is over Bert is about the start the 6th grade, and Klimpen will move to Motala.