OBJECTIVES: To investigate the horizontal equity concerning the use of primary healthcare services in Greece in 2006 and in 2011. Given that the economic crisis affects the healthcare system in Greece, the comparison between the findings depicts the post-crisis effects on the use of primary health care services. METHODS: The research is based on two cross-sectional surveys, which took place in 2006 and in 2011, and the sample size was 4003 and 6569 respectively. Moreover, a random, stratified sampling was applied in both cases, which took into account the age, the gender, the urbanization rate and the geographical region. RESULTS: The Concentration Index for the measurement of horizontal equity (CHE) can be estimated as CU-CN. The CU index depicts the use of primary healthcare services, based on the number of medical visits. Additionally, the CN index intends to specify the use of primary healthcare services in terms of need for care. It is also noteworthy that CN was estimated after applying the Poisson Regression method (dependent variable: use of primary healthcare services, independent variables: self assessed health status and chronic health problems). According to the results, CHE was -0.06 in 2006, as CU and CN were estimated at -0.14 and -0.08 respectively. Furthermore, CU was -0.06, while CN was estimated at -0.04 in 2011. Therefore CHE decreased to -0.02. CONCLUSIONS: The low-income individuals tend to use primary healthcare services more than the high-income individuals, regardless the economic crisis. This finding can be explained, as the low income is usually accompanied with a lower health status. Generally, as CHEis close to zero, there are not strong indications of inequality. However, CHE increased in 2011 (closer to zero), which implies that the inequality shifted from higher income individuals.