The descriptive cross-sectional survey conducted on 210 mothers raising children 24 months of age on their knowledge on family planning methods in Phu Tho province. The results showed that: The mothers who know at least 3 modem methods of contraception was found at a high rate (84.8 percent), in the highest rate was found for condoms (98.1 percent). The rate of mothers who answered cprrectly on the time of use contraception after birth is still low, while 3.3 percent of the mothers did not know about when to use contraception after birth. Most of the mothers know where to buy or get condoms. Commune health centers and pharmacies are the two addresses which are most known (at the same rate of 86.7 percent), the rest ones are population, village health workers (76.2 percent) and private clinics (0.5 percent). However, while 1.9 percent of the mothers did not know where they can buy/receive condoms. Most of the mothers khew about where to buy or get oral pills
commune health centers and pharmacies are also the two most addresses (87.1 percent and 88.1 percent, respectively). The top reason why condoms have been not widely used are that people are afraid of condom side effects (59.5 percent). And reason why oral pills have been rarely used is that people may forget to use (81.4 percent).