Objective: The aim was to analyze the use of Information System of Primary Care (SIAB) for planning and evaluation of actions in Family Health Units. Method: A descriptive and qualitative study, conducted from January to June 2008, in the units of the Health District IV in Campina Grande-PB. Interviews were conducted with four practitioners medical and six nurses. Results: Four categories emerged: The work at the Family Health Strategy; The assessment of the Information System of Primary Care by family heath professionals; Training for use of Information System of Primary Care; and Use of Information System of Primary Care in planning and evaluation of local health activities. It was found that use of the SIAB boils down to filling in forms and reporting what is claimed by the Health Department. Conclusion: Information not have supported the planning and assessment of actions, nor they not have been added reflectively to routine services.