Radiotherapy has been associated with an increased risk for cardiovascular disease (CVD) in Hodgkin lymphoma survivors (HLS). Identifying subjects most likely to develop these complications is challenging. Arterial stiffness has been frequently used as an early marker of CVD, but has never previously been investigated in patients treated with radiotherapy. The carotid-femoral pulse wave velocity (PWV) and the distensibility coefficient (DC) of the common carotid artery were used as markers of arterial stiffness. Eighty-two HLS and 40 age- and gender-matched control subjects were studied. The aorta and the carotid arteries were situated within the radiation field in 50 and 39 patients. Mean PWV was not significantly different in HLS treated with radiotherapy on the mediastinum when compared to HLS treated without mediastinal radiotherapy and to controls. If HLS were 40 years or older at radiotherapy their PWV was significantly higher (8.54 m/s) than patients irradiated at a younger age (7.14 m/s, p = 0.004) and controls (6.91 m/s, p < 0.001), after adjusting for current age and other CVD risk factors. Mean DC was lower, indicative of stiffer arteries, in HLS treated with radiotherapy on the common carotid artery (2.79) than in HLS without radiotherapy (3.35, p = 0.029) and versus controls (3.60, p = 0.001). DC was lowest in HLS treated at 35 years of age or later (2.05), compared to HLS irradiated at a younger age (2.98, p = 0.046). In HLS, radiotherapy is associated with increased arterial stiffness. The effect of radiotherapy seems most evident when radiotherapy is administered at ages above 35-40 years.