Background Chronic pancreatitis (CP) is a fibro-inflammatory disease of the pancreas. Early diagnosis and intervention, before CP becomes established and irreversible, are essential to improve the long-term outcomes. The world’s first diagnostic criteria for early CP were proposed in Japan in 2009, but their clinical utility remains elusive. This study aimed to clarify whether patients with early CP progress to definite CP. Methods This is a multicenter, prospective study. Patients diagnosed as having early CP according to the Japanese diagnostic criteria were prospectively followed for 2 years. Clinical profiles including symptoms, drinking and smoking status, laboratory data, imaging findings and treatments were analyzed. Results Among the 83 patients who completed the 2-year follow-up period, four (4.8%) patients progressed to definite CP. The diagnosis of 48 (57.8%) patients was unchanged, and that of 31 (37.3%) patients was downgraded. All the four progressive patients were male, alcohol-related, smokers (3 current and 1 ever), and continued drinking. Comparison of the clinical profiles between the progression group ( n  = 4) and non-progression group ( n  = 79) revealed that etiology (alcohol-related), smoking status and presence of acute pancreatitis episodes were associated with the progression to definite CP. Conclusions The Japanese diagnostic criteria could identify some patients before the progression to definite CP, while the majority of the patients did not progress. Trial registration number: UMIN000015992.