In this study we investigated the factors associated with pre-hospital delay to treat acute ischemic stroke and transient attack with intravenous recombinant tissue-plasminogen activator (rt-PA) in Japan. In 625 patients, we investigated the pathways and times of their arrival to our hospital, and the significant and independent factors in the patients' clinical backgrounds associated with delayed arrival (>2 h after notice). In total, 287 patients arrived at our hospital directly via EMS, 113 came by themselves, and 225 transferred from other institutes. Delayed arrivals occurred in 423 patients (68%). Multivariate analyses showed that staying in another hospital at notice, a worsened course, and referral from other institutes were positively related, and evening onset, having a witness at onset, loss of consciousness, and using EMS were negatively related to delayed arrival; a worsened course was positively related, and staying in other hospital at notice, having a witness at onset, loss of consciousness, and a high NIHSS on admission were negatively related to delayed alert; hypercholesterolemia and onset in a nursing home were positively related, and staying in other hospital at notice, loss of consciousness, and a high NIHSS on admission were negatively related to not using EMS. A lack of knowledge concerning stroke emergency by medical staff as well as the general public may be responsible for some stroke patients losing the chance for rt-PA treatment.