The aim of this study was to evaluate Cryptosporidium spp. contamination of sea and tap water samples from Sinop and Ordu Provinces, Black Sea, Turkey. The samples (10 L) were collected in spring, summer, autumn, and winter in 2011. A total of 128 water samples was analyzed using an immunofluorescence test (IFT), as well as loop-mediated isothermal amplification (LAMP) and nested polymerase chain reaction (PCR). Cryptosporidium spp. oocysts were detected by IFT in 43 of the 70 samples (61.4%; 1–40 oocysts per 0.5 L) and 35 of the 58 samples (60.3%; 1–23 oocysts per 0.5 L) in the sea water samples from Ordu and Sinop, respectively. The highest number of oocysts by IFT were detected in spring and winter in Ordu and Sinop, respectively. The results of the S-adenosylmethionine synthetase (SAM) gene LAMP assays were 65.5% positive for Cryptosporidium parvum, Cryptosporidium hominis, and Cryptosporidium meleagridis in all examined samples, while the SSUrRNA gene nested PCR assay was 31.0% positive. Six C. parvum nested PCR products from all positive samples were successfully sequenced.