This dataset contains anonymized quantitative data from a nationally oriented survey conducted in Switzerland as part of the ICOCO project (Intergenerational Cohesion during COVID-19 and beyond: https://data.snf.ch/grants/grant/209885). The survey investigates intergenerational relationships within families, with a focus on contact patterns, communication modes, support exchanges, and perceptions during and after the COVID-19 pandemic. Data were collected between January and March 2025 using a mixed-mode design combining computer-assisted web interviewing (CAWI) and paper-and-pencil interviewing (PAPI) to ensure inclusivity across age groups. The sampling frame was based on address data provided by the Swiss Federal Statistical Office, drawing on the Swiss Household Panel. The dataset includes responses from N = 1,205 individuals aged 18 and older living in Switzerland who reported having at least one living family member (grandparent, parent, child, or grandchild). The sample has a mean age of 52.4 years (SD = 18.0; range: 19–102). The questionnaire consists of standardized, closed-ended items covering: Frequency and modes of intergenerational contact (face-to-face, telephone, digital communication) Perceived changes in contact and relationship quality during and after the COVID-19 pandemic Intergenerational support exchanges Attitudes toward COVID-19 measures and perceived stress Digital communication skills and preferences Sociodemographic characteristics All data have been fully anonymized prior to release. A codebook is also provided.