Objectives: Follow changing physical activity (PA) patterns among women and men during pregnancy compared to before pregnancy. Study design: Longitudinal study. Methods: The study involved 280 individuals, 145 women and 135 men (who were partners to the women), from the municipality of Karlskrona, Sweden. Data were collected during 2008–2009. We measured the self-reported amount of PA performed outdoors and indoors during the 12 months before pregnancy and throughout the entire pregnancy. Results: Among both women and men, we found changes in PA patterns during pregnancy compared to before pregnancy. Women and men were more physically active before pregnancy than during pregnancy. Similar patterns were found among women and men with regard to the type of activity, with both groups taking more exercise and pursuing aquatic sports, indoor PA and non-strenuous activities before pregnancy and more strolling/walking during pregnancy. Conclusions: Our findings contribute new knowledge about changes in men’s PA patterns from pre-pregnancy to pregnancy that is an unexplored field. Changes in the women’s activity patterns during pregnancy also affect the men. Women seem to adjust their activity patterns during the pregnancy. The changes in activity patterns among the men are more tentative but follow the pattern for the women, which could be explained by the couples sharing their everyday lives. Midwives should consider providing information to men about the importance of being physically active during pregnancy and informing them about their role in encouraging women to be physically active.