The Mandaic alphabet is based on the Aramaic alphabet, and is used for writing the Mandaic language.

The Mandaic name for the script is Abagada or Abaga, after the first letters of the alphabet. Rather than the ancient Semitic names for the letters (alaph, beth, gimal), the letters are known as â, bâ, gâ and so on.

The alphabet consists of 24 letters: the 22 letters of the Aramaic alphabet with two additional letters at the end. As the number 24 is auspicious for Mandaeans (it is the number of hours from sunset to sunset), the additional letters are somewhat artificial. The 23rd letter is adu, the relative particle (cf. Arabic tāʾ marbūṭa, Coptic letter "ti", and English ampersand). And the 24th is the first letter, a, repeated. Thus, Mandaeans say that the abagada has perfected the alpha and omega.

Unlike most other Semitic alphabets, the vowels are usually written out in full. The first and last letter, a (corresponding to alaph), is used to represent a range of open vowels. The sixth letter, wa, is used for close back vowels (u and o), and the tenth letter, ya is used for close front vowels (i and e). These last two can also serve as the consonants w/v and y. The eighth letter corresponds to the Semitic heth, and is called eh; it always is pronounced as a long i-vowel, but is rarely used as it is thought to be a sacred representation of the eye of God. A similar situation exists for the sixteenth letter, e (Aramaic ayn), which usually represents e at the beginning of a word, or, when followed by wa or ya, for initial u or i respectively.