We have performed two campaigns of intensive monitoring of the blazars 3C 273, 3C 279, and PKS 1510‐089 in the X‐ray, optical, near‐IR, and radio regions in March and April 2002. The quasar 3C 279 reveals significant interday variability at all wavelengths. The quasar 3C 273 shows smooth variations in the X‐ray and near‐IR regions on time scales of 2–3 days. For both quasars the results indicate close connection between X‐ray and near‐IR emission with a delay of X‐rays from 0 to 3 days. The quasar PKS 1510‐089 was in a low emission state at all frequencies during the campaigns.