In a healthcare system with equal access we analysed possible associations between cancer survivors’ socioeconomic status (SES) and their: 1) need for rehabilitation; 2) participation in rehabilitation activities; and 3) unmet needs for rehabilitation in a 14-month period following date of diagnosis. A population-based cohort study including incident cancer patients diagnosed from 1 October 2007 to 30 September 2008 in Denmark. Fourteen months after diagnosis participants completed a mailed out questionnaire developed to measure different aspects and dimensions of rehabilitation. Individual information on cohabitation status, education, income and labour market status was retrieved from national registers. Logistic regression analyses were used to explore associations between socioeconomic status and rehabilitation outcomes. A total of 3439 patients responded (70%). Significant interactions between SES and sex were demonstrated and further analyses were therefore stratified for gender. In general, women and to a lesser extent men with short education and low income participated less often in activities and had in some areas more unmet needs. Women living alone more often expressed a rehabilitation need in the physical, emotional and financial area and had to a higher extent unmet needs in a number of areas. Men living alone and men outside the workforce had increased odds of unmet needs in the physical area. Despite equal access to care, SES had a significant impact on cancer survivors’ rehabilitation. In general, the associations were most pronounced for female cancer patients. We suggest that special attention should be paid to socioeconomically disadvantaged groups by taking into account differences in SES in a clinical setting and when developing targeted rehabilitation programmes.