AIM: To observe the imaging features of color Doppler ultrasound (CDU) and computed tomography (CT) or computed tomography dacryocystography (CT-DCG) in different types of lacrimal sac space-occupying lesions (SOLs). METHODS: This retrospective case series study included 21 patients with lacrimal sac SOLs who underwent lacrimal sac surgery between January 2018 and March 2022. The imaging features of CDU and CT or CT-DCG in these patients were extracted from the examination cloud system. The images were observed and analyzed. RESULTS: The detection rate of lacrimal SOLs between CDU (21/21, 100%) and CT or CT-DCG (20/21, 95.2%) had no statistically significant difference (P=1.0). CDU could detect the blood flow signals in all SOLs except mucocele and mucopeptide concretion. Among them, polyps had characteristic imaging changes on CDU and CT-DCG. The mucoceles and mucopeptide concretions had characteristic imaging changes on CDU, which could provide more information for differential diagnosis. CONCLUSION: The morphology and internal blood flow signals of lacrimal sac SOLs can be observed using CDU. CT or CT-DCG has advantages in observing structural damage around the lacrimal sac mass. Therefore, CDU may be used as a routine examination to exclude lacrimal sac SOLs before dacryocystorhinostomy in the absence of preoperative CT or CT-DCG.